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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => LAB Subwoofer Forum => Topic started by: Alex Berry on May 28, 2015, 09:06:43 pm

Title: Choosing the best sub for me
Post by: Alex Berry on May 28, 2015, 09:06:43 pm
First of all, I'd like to thank you all in advance for taking the time to help me out.

My company is currently looking to invest in some scalable, loud single driver subwoofers. Essentially, anything that can get as loud as or louder than the average dual 18 (average dual 18 defined as doing around 133db continuous) and is a single driver box is on the table. We do primarily EDM events, so the subs need to be well able to play to this demanding style of music. The single driver form factor is derived from the fact that we'd love to have a sub that we can take to smaller DJ events and put one on either side of our 6 foot table, but then could be easily scaled to provide for larger events.

I've currently been looking into specifically the dB Technologies S1521N, and the Danley TH-118, but the Danley has some things that go along with it that scare me. Like the fact that tapped horn boxes need to have the tops delayed a certain way to sound correct, and that every frequency has a different delay time, along with the fact that I don't currently have a way to delay my tops, so that piece of external DSP would need to be factored into the final cost. Also the fact that the Danley has almost no handles puts me off a bit. I get that the Danley isn't the correct form factor, but one under the table for small events would be absolutely perfect.

I also just in the past hour found the Wharfedale Focus-18S, which looks on paper to be promising. 35hz at -6db, an averaged sensitivity of 104db coupled with a 1000wrms rating would give it a continuous output of 134db. Although I'm very sceptical to how they were able to get 104db of sensitivity out of a simple bass reflex cab. Thoughts on this, the other subs I've listed, and any others that fit this critera are very much welcomed. I'm not afraid to be told that I've been looking in the wrong place and need to take a completely different approach ;)

I'd like to keep the price per box somewhere around $3k per box. Although like with the Danley, after amplification the total would be a bit higher than that, and that would be acceptable.
Title: Re: Choosing the best sub for me
Post by: TJ (Tom) Cornish on May 28, 2015, 09:30:23 pm
First of all, I'd like to thank you all in advance for taking the time to help me out.

My company is currently looking to invest in some scalable, loud single driver subwoofers. Essentially, anything that can get as loud as or louder than the average dual 18 (average dual 18 defined as doing around 133db continuous) and is a single driver box is on the table. We do primarily EDM events, so the subs need to be well able to play to this demanding style of music. The single driver form factor is derived from the fact that we'd love to have a sub that we can take to smaller DJ events and put one on either side of our 6 foot table, but then could be easily scaled to provide for larger events.

I've currently been looking into specifically the dB Technologies S1521N, and the Danley TH-118, but the Danley has some things that go along with it that scare me. Like the fact that tapped horn boxes need to have the tops delayed a certain way to sound correct, and that every frequency has a different delay time, along with the fact that I don't currently have a way to delay my tops, so that piece of external DSP would need to be factored into the final cost. Also the fact that the Danley has almost no handles puts me off a bit. I get that the Danley isn't the correct form factor, but one under the table for small events would be absolutely perfect.

I also just in the past hour found the Wharfedale Focus-18S, which looks on paper to be promising. 35hz at -6db, an averaged sensitivity of 104db coupled with a 1000wrms rating would give it a continuous output of 134db. Although I'm very sceptical to how they were able to get 104db of sensitivity out of a simple bass reflex cab. Thoughts on this, the other subs I've listed, and any others that fit this critera are very much welcomed. I'm not afraid to be told that I've been looking in the wrong place and need to take a completely different approach ;)

I'd like to keep the price per box somewhere around $3k per box. Although like with the Danley, after amplification the total would be a bit higher than that, and that would be acceptable.
Danley boxes - at least on this forum suffer from a little TMI - too much information, that can actually cloud the issue.  The reality is that every subwoofer needs to be time aligned to the mains to work correctly, and unless you're buying subs that match your mains (what are those, by the way?), the Danley is not at a disadvantage.  That every frequency has a different delay time is also true of every speaker, but in practice this isn't a big issue if the subs are physically close to your mains.

The TH-118 is arguably the best subwoofer of its size on the planet.  The form factor is extremely convenient.  They roll very easily, and can easily be tipped on their side, into a van, etc.  Smaller subs in many cases are harder to move than the TH-118s. 

There are only three reasons I can think of to not get TH-118s:

- $$$
- If you already have a high-quality system, getting the matching subs can be a good idea
- rider acceptability (even this is becoming less of a problem as folks get more familiar with the product)

Other than those potential factors, the TH-118 should be at the top of your list.

Sincerely,
TJ Cornish
Danley TH-118 owner/lover
Compact Line Array Enthusiast
Occasional Danley Employee Forum Behavior Criticizer
Title: Re: Choosing the best sub for me
Post by: Alex Berry on May 28, 2015, 09:41:45 pm
Danley boxes - at least on this forum suffer from a little TMI - too much information, that can actually cloud the issue.  The reality is that every subwoofer needs to be time aligned to the mains to work correctly, and unless you're buying subs that match your mains (what are those, by the way?), the Danley is not at a disadvantage.  That every frequency has a different delay time is also true of every speaker, but in practice this isn't a big issue if the subs are physically close to your mains.

The TH-118 is arguably the best subwoofer of its size on the planet.  The form factor is extremely convenient.  They roll very easily, and can easily be tipped on their side, into a van, etc.  Smaller subs in many cases are harder to move than the TH-118s. 

There are only three reasons I can think of to not get TH-118s:

- $$$
- If you already have a high-quality system, getting the matching subs can be a good idea
- rider acceptability (even this is becoming less of a problem as folks get more familiar with the product)

Other than those potential factors, the TH-118 should be at the top of your list.

Sincerely,
TJ Cornish
Danley TH-118 owner/lover
Compact Line Array Enthusiast
Occasional Danley Employee Forum Behavior Criticizer

What I meant by delaying the Danley box was that I was under the impression that tapped horns have an inherrent delay, and that if the tops were lined up right next to the subs, you'd have to delay the tops to have them be aligned properly with the subs. As compared to bass reflex boxes, you don't have to do this.

My tops currently are EV ZLX-12P's, although I'd be using whatever subs we end up purchasing with a wide variety of tops. Be it QSC KW153, EV ETX-35P, and down the line we're looking at investing into a dB Tech T8 array, so we would use the subs with them as well.

Another factor worth considering would be that for the foreseeable future the sub(s) will be stored in a basement and in turn need to be carried up and down a flight of stairs. If I were to go with the Danley, I would probably just buy a stair dolly or something to deal with this.
Title: Re: Choosing the best sub for me
Post by: Mac Kerr on May 28, 2015, 10:04:43 pm
What I meant by delaying the Danley box was that I was under the impression that tapped horns have an inherrent delay, and that if the tops were lined up right next to the subs, you'd have to delay the tops to have them be aligned properly with the subs. As compared to bass reflex boxes, you don't have to do this.

All subs have an inherent delay. It is caused by the phase shift in the low pass filter in the crossover between the subs and the mains. If you use an 80Hz crossover the wavelength is about 14ft. A 12dB/octave filter will have a 180║ phase shift, which at 80Hz will be half a wavelength, or about 7ft. That is just the crossover, so it happens with all speakers that you use a 12dB/oct crossover with.

This a very simplistic explanation of a more complex phenomenon, but maybe it helps make clear that lining up the fronts of front loaded boxes does not mean the output of them will match in phase.

Mac
Title: Re: Choosing the best sub for me
Post by: TJ (Tom) Cornish on May 28, 2015, 10:11:42 pm
What I meant by delaying the Danley box was that I was under the impression that tapped horns have an inherrent delay, and that if the tops were lined up right next to the subs, you'd have to delay the tops to have them be aligned properly with the subs. As compared to bass reflex boxes, you don't have to do this.

My tops currently are EV ZLX-12P's, although I'd be using whatever subs we end up purchasing with a wide variety of tops. Be it QSC KW153, EV ETX-35P, and down the line we're looking at investing into a dB Tech T8 array, so we would use the subs with them as well.

Another factor worth considering would be that for the foreseeable future the sub(s) will be stored in a basement and in turn need to be carried up and down a flight of stairs. If I were to go with the Danley, I would probably just buy a stair dolly or something to deal with this.
If you're getting into boxes the size of 3-way mains or T8s, you'll have other issues getting boxes upstairs.

I have owned single-18 subs, and carrying them up stairs isn't any fun either.  With a second person, the TH-118's aren't a big deal to go up stairs - one person grabs the handles, the other grabs the casters.

In addition to delay (all subs require time alignment), you're going to need a crossover and EQ, so you're into a DSP or DSP amp anyway.
Title: Re: Choosing the best sub for me
Post by: Alex Berry on May 28, 2015, 10:31:29 pm
All subs have an inherent delay. It is caused by the phase shift in the low pass filter in the crossover between the subs and the mains. If you use an 80Hz crossover the wavelength is about 14ft. A 12dB/octave filter will have a 180║ phase shift, which at 80Hz will be half a wavelength, or about 7ft. That is just the crossover, so it happens with all speakers that you use a 12dB/oct crossover with.

This a very simplistic explanation of a more complex phenomenon, but maybe it helps make clear that lining up the fronts of front loaded boxes does not mean the output of them will match in phase.

Mac

Taking the phase shift of a crossover out of the equation, does a tapped horn box have an inherrent delay due to the physical design compared to a bass reflex box which doesn't?

I was actually unaware that crossovers added that much phase shift.

If you're getting into boxes the size of 3-way mains or T8s, you'll have other issues getting boxes upstairs.

I have owned single-18 subs, and carrying them up stairs isn't any fun either.  With a second person, the TH-118's aren't a big deal to go up stairs - one person grabs the handles, the other grabs the casters.

In addition to delay (all subs require time alignment), you're going to need a crossover and EQ, so you're into a DSP or DSP amp anyway.

I'll always have a second person to help me carry the sub when needed, and after your simple explanation I've come to the realization that carrying the Danleys would be much easier than I previously thought. So thanks for that! Sometimes I miss the really simple things.

All of the amps I've been looking at so far at the very least have crossover control built in. Why would I need EQ though, AFAIK I could just low pass the Danley and let it run and it'd be fine. Especially after looking at the published frequency response for the box.

Although a big concern about the Danley would be that if I just got one now, if it broke I wouldn't have a backup. If I got two smaller subs, if one broke I would have a backup.

Lets throw another sub onto the chopping block. What about the Martin Audio WS18X, that thing looks promising as well.
Title: Re: Choosing the best sub for me
Post by: Lee Buckalew on May 28, 2015, 10:58:27 pm
Lets throw another sub onto the chopping block. What about the Martin Audio WS18X, that thing looks promising as well.

I like the WS18X but have never compared it side by side to the TH118.  Who is your rep for each of these?  Ask them for a demo so you can judge for your use.

Lee
Title: Re: Choosing the best sub for me
Post by: Mac Kerr on May 29, 2015, 12:11:10 am
Taking the phase shift of a crossover out of the equation,

How do you do that? Do you not have a crossover between the subs and mains? It can be an external line level crossover, or a passive high level crossover inside the speaker cabinet, but it will do the same thing. Getting subs and mains in phase through the crossover region involves more than lining up the front of the boxes.

Yes, because of the path length of a horn type sub there will be additional delay involved in lining up a horn sub, but who cares once you have made the effort to do an alignment at all.

Mac
Title: Re: Choosing the best sub for me
Post by: Alex Berry on May 29, 2015, 12:48:23 am
I like the WS18X but have never compared it side by side to the TH118.  Who is your rep for each of these?  Ask them for a demo so you can judge for your use.

Lee

After doing a bit more research I'm starting to consider investing into a Martin H3+ rig down the line instead of a dB Tech T8 rig. This would push me much further towards wanting to get the WS18X because not only would it go great with the H3+, but it could easily be paired with the WS218X. As attractive as the Danley is, having a full Martin system is more attractive. And even further down the line I'd probably invest into their line arrays too.

I haven't talked to my dealers in my area yet, but the dB Tech/Martin dealer that covers my area is Audio Associates, and the Danley dealer is Lienau AV Associates. I'm kinda new to this, but I'm not exactly sure how OK both companies would be with demoing speakers for me at the same time.

How do you do that? Do you not have a crossover between the subs and mains? It can be an external line level crossover, or a passive high level crossover inside the speaker cabinet, but it will do the same thing. Getting subs and mains in phase through the crossover region involves more than lining up the front of the boxes.

Yes, because of the path length of a horn type sub there will be additional delay involved in lining up a horn sub, but who cares once you have made the effort to do an alignment at all.

Mac

I never said that I was going to not run a crossover in an actual real life scenario, you were missing the point. I've run many bass reflex subs before, and never delayed them to the tops to compensate for phase shift in the crossover, and never thought the subs sounded out of phase from the tops. At the same time, wouldn't the tops be experiencing the same phase shift due to their crossover as well? If the Danley box has MORE delay due to its design even on top of the delay caused by the crossover, that's just something else that I have no idea how to deal with. That's something that bass reflex cabs don't have.
Title: Re: Choosing the best sub for me
Post by: Mac Kerr on May 29, 2015, 01:08:42 am
I never said that I was going to not run a crossover in an actual real life scenario, you were missing the point. I've run many bass reflex subs before, and never delayed them to the tops to compensate for phase shift in the crossover, and never thought the subs sounded out of phase from the tops. At the same time, wouldn't the tops be experiencing the same phase shift due to their crossover as well? If the Danley box has MORE delay due to its design even on top of the delay caused by the crossover, that's just something else that I have no idea how to deal with. That's something that bass reflex cabs don't have.

You are missing the point. Due to the phase shift in the crossover your subs did not have a good phase alignment even though you lined up the fronts. If you want to do a phase alignment using delay to get the subs and mains corrected through the crossover range it hardly matters whether you are adjusting for 7ms or 15ms. On the other hand, if you don't care about the phase alignment, and for years hardly anyone was even aware of it, it won't sound terrible with either type of speaker. Choose a speaker type for its performance characteristics, not its latency.

Mac
Title: Re: Choosing the best sub for me
Post by: Alex Berry on May 29, 2015, 01:14:56 am
You are missing the point. Due to the phase shift in the crossover your subs did not have a good phase alignment even though you lined up the fronts. If you want to do a phase alignment using delay to get the subs and mains corrected through the crossover range it hardly matters whether you are adjusting for 7ms or 15ms. On the other hand, if you don't care about the phase alignment, and for years hardly anyone was even aware of it, it won't sound terrible with either type of speaker. Choose a speaker type for its performance characteristics, not its latency.

Mac

I fully understand what you are saying. However, if the bass reflex subs are theoretically phase shifted by x amount from the tops and sound fine, the tapped horn subs would be even more out of phase and potentially not sound fine. Unless you're saying the amount of latency involved here doesn't make an audible difference.

Also, if you applied an 80hz HPF to your tops and a 80hz LPF to your subs, wouldn't your tops and your subs be phase shifted the same amount, therefore staying in phase and making this entire point irrelavent?

Title: Re: Choosing the best sub for me
Post by: Lee Buckalew on May 29, 2015, 06:02:36 am
After doing a bit more research I'm starting to consider investing into a Martin H3+ rig down the line instead of a dB Tech T8 rig. This would push me much further towards wanting to get the WS18X because not only would it go great with the H3+, but it could easily be paired with the WS218X. As attractive as the Danley is, having a full Martin system is more attractive. And even further down the line I'd probably invest into their line arrays too.

I haven't talked to my dealers in my area yet, but the dB Tech/Martin dealer that covers my area is Audio Associates, and the Danley dealer is Lienau AV Associates. I'm kinda new to this, but I'm not exactly sure how OK both companies would be with demoing speakers for me at the same time.

You are not considering similar technologies at all if you are looking at H3+ vs. T8.  T8 is a line array system and is relatively recent in terms of technological development.  Martin has some very good options along those lines but...H3+ is not one of them.  H3+ is a dance club box built with a slightly older school technology that still works great for clubs when you are dealing with EQ curves designed around the sonic perceptions of those with altered realities.
It sounds to me like you need to define your needs and then look at what systems will answer those needs.

Dealers or reps should not have a problem demoing side by side if you are serious about buying and if you are comparing somewhat similar products.  That said, they aren't going to come out and set up a couple of $250.00 speakers but they may send them to you to try.  The speakers that you are talking about represent a significant enough investment that I would think dealers or reps could work out a demo for you.

As far as subs go, the WS18X and the WS218X can work nicely together.  From a cabling perspective think it through.  WS18X has an NL8 with +1+2 & -1-2 feeding the driver and +3/-3, +4/-4 passing through.  The WS218X uses +1+2, -1-2 to feed driver 1 and +3+4, -3-4 to feed driver 2. 
Keep in mind that there is no problem with utilizing subs from one manufacturer and mains/tops from another.  Don't knock Danley out of the running without hearing it.

Listen to what Mac is saying about phase relationships.  Learning more about the interactions of your speaker systems with each other and with their processing can only help you do a better job.

Lee
Title: Re: Choosing the best sub for me
Post by: TJ (Tom) Cornish on May 29, 2015, 07:06:43 am
I fully understand what you are saying. However, if the bass reflex subs are theoretically phase shifted by x amount from the tops and sound fine, the tapped horn subs would be even more out of phase and potentially not sound fine. Unless you're saying the amount of latency involved here doesn't make an audible difference.

Also, if you applied an 80hz HPF to your tops and a 80hz LPF to your subs, wouldn't your tops and your subs be phase shifted the same amount, therefore staying in phase and making this entire point irrelavent?
Alex, we're struggling with inconsistent signals from you. On one hand you have a tight budget where you can't afford a DSP, then you are shopping for dB T8 or Meyer stuff. On one hand you are shopping for touring class boxes, but on the other you're willing to throw out the TH-118 because it needs slightly different processing than other subs (which need their own processing too).

All subs need time alignment, EQ, and high and low pass filters. ALL OF THEM. Some products are prepackaged with this built-in if they are a powered box designed to work with a particular main box, but other than that, external processing is required. For that matter, you probably need DSP on your mains to work with the subs from that direction, too.

Many amps these days basically throw in DSP capability for free. If you have a non-DSP amp, DSP functionality can be had for just a couple hundred dollars from a Behringer DCX-2496. Setting that up requires a little skill, or you can hire someone to help you once, then save those settings for use the rest of the time. For best performance of your many-thousand dollar rig, this is required no matter what subs or mains you end up with.
Title: Re: Choosing the best sub for me
Post by: Ivan Beaver on May 29, 2015, 07:46:05 am

Although a big concern about the Danley would be that if I just got one now, if it broke I wouldn't have a backup. If I got two smaller subs, if one broke I would have a backup.


And if you get 2 "weaker subs", you will be pushing them harder-meaning they will be more likely to break.

And the whole time you own them you will be getting output and low freq extension.

Do you also carry twice the top boxes-twice the amps-2 DJ mixers and so forth?

What if they break?
Title: Re: Choosing the best sub for me
Post by: Ivan Beaver on May 29, 2015, 07:57:51 am
Everything people have said about the inherent delay caused by the crossover filters and such is true.

But in the "ol days" we did not have delay to line up bevices-and i t worked just fine.

People often confuse "being perfectly acceptable" and "perfect".

In most cases if you run a full range cabinet with a TH118, all you have to is reverse the polarity of the TH118 and you will be perfectly fine.

It won't be "as good as" it could be-but you are probably 90% there.

Having delay available to you -and not have a measurement system and knowledge to use it, is only a guess.  Unless you are dealing with known quantities.

It is easy to get all "worried" about the little things that really don't matter to most people.

YES, it all the little things that ADD UP to a great sound, but only looking at one of them is not going to somehow magically make it sound better.

In my opinion-in your setup, I would not worry about it.

Flip the polarity and have a good day :)

HOWEVER, just be forwarned that "Flipping the polarity" is a SUGGESTION.  What is actually best depends on the rest of the system-how the crossover is setup and so forth.

The BEST way is to LISTEN to it with the polarity flipped and normal and then determine what give you the best "sound".

This applies to ANY sub/top combination.  Sometimes you will trade low freq for punch.  YOU have to make that call.

Maybe not a good analogy, but worrying about the delay time is like choosing a car depending on what oil it uses---------------

They all need it, and you can change types-it is not the end of the world or a reason to choose a different car.  Color is more important-------- :)

OK before the car guys get involved-YES I understand the differences in oil, but was trying to make a simple analogy-that was what came to mind.
Title: Re: Choosing the best sub for me
Post by: Alex Berry on May 29, 2015, 10:17:55 am
You are not considering similar technologies at all if you are looking at H3+ vs. T8.  T8 is a line array system and is relatively recent in terms of technological development.  Martin has some very good options along those lines but...H3+ is not one of them.  H3+ is a dance club box built with a slightly older school technology that still works great for clubs when you are dealing with EQ curves designed around the sonic perceptions of those with altered realities.
It sounds to me like you need to define your needs and then look at what systems will answer those needs.

You're right that they're very different options, but for my use case I think the Martin would be better suited. The system my company is looking to invest into would be used mainly for 500-1000 person EDM party type events. Basically small local EDM concerts. I loved the T8 because it's versatile, scalable, and loud enough to do the job. It could also be used for a wide variety of other events. I also couldn't think of any trap boxes that would be loud enough to do the job other than the EAW KF850 and the RCF 4PRO 6001-A, but I was already looking at getting dB Tech subs and I liked the thought of the versatility that came with a line array. Now, after really looking back on it, I think I like the Martin cab better for this use case. It's a lot cheaper while it should be as loud as a 4x T8 hang that's splayed to cover the same area, and since we do a lot of school related events, for homecomings we could potentially use it as a selling point. "We have the same sound system as one of the best sounding dance clubs in America! (U Street Music Hall)" Although, if you're saying the box is only really good for clubs with certain EQ's, I might have to reconsider.

Quote
Dealers or reps should not have a problem demoing side by side if you are serious about buying and if you are comparing somewhat similar products.  That said, they aren't going to come out and set up a couple of $250.00 speakers but they may send them to you to try.  The speakers that you are talking about represent a significant enough investment that I would think dealers or reps could work out a demo for you.

Thanks for the info. How exactly do I go about asking them to do that? When I email them both do I just tell them that I'm interested in hearing both speakers and am wondering if they'll be willing to let me A/B them?

Quote
As far as subs go, the WS18X and the WS218X can work nicely together.  From a cabling perspective think it through.  WS18X has an NL8 with +1+2 & -1-2 feeding the driver and +3/-3, +4/-4 passing through.  The WS218X uses +1+2, -1-2 to feed driver 1 and +3+4, -3-4 to feed driver 2. 
Keep in mind that there is no problem with utilizing subs from one manufacturer and mains/tops from another.  Don't knock Danley out of the running without hearing it.

I'd be more interested in having the WS18X supplement a WS218X rig if it was needed, rather than planning on using them together from the get go. I would also have seperate amps for the WS18X's because they would be a part of my "small" system.

As for a mismatched system, trust me, I know! In February I used SoundBridge 7218SWX's along side EV ETX-35P's for mains and ZLX-12P's for front fills, and for years I'd used Behringer subs with no name MTX tops. The thing is, a matching system is a matching system. No matter how illogical it is, it's a matching system. I'm also not the person who makes the final call. If my boss likes the idea of a matching system better, then that's the route we'll be taking. But he'll also be there with me when we demo the subs, so the Danley will definitely have it's chance.

Quote
Listen to what Mac is saying about phase relationships.  Learning more about the interactions of your speaker systems with each other and with their processing can only help you do a better job.

Lee

I have been! I was never arguing with him about whether or not a crossover caused a phase shift, I was simply trying to get the point across that I don't know how to deal with the extra phase shift inherent to a tapped horn box. But Ivan's already told me that it's basically not an issue, and a basic way of how to deal with it if I need to.


Alex, we're struggling with inconsistent signals from you. On one hand you have a tight budget where you can't afford a DSP, then you are shopping for dB T8 or Meyer stuff. On one hand you are shopping for touring class boxes, but on the other you're willing to throw out the TH-118 because it needs slightly different processing than other subs (which need their own processing too).

I'm not quite sure where you got the idea that I couldn't afford a DSP, as I was looking at getting one anyways. I was being put off from the Danley because I don't know how to deal with it's extra phase shift. I guess I really wasn't making that clear. Bassreflex cabs don't need that extra processesing, at least in my experience they haven't. However with having no experience with the Danley, I have no idea what I'm getting into and no idea how to deal with a potential problem. Although Ivan has already well informed me that it's pretty much not an issue, and that I shouldn't worry about it. Telling me that all subs need delay doesn't help me when I've already used plenty of subs, only delaying them to match the tops in terms of physical distance differences.

Quote
All subs need time alignment, EQ, and high and low pass filters. ALL OF THEM. Some products are prepackaged with this built-in if they are a powered box designed to work with a particular main box, but other than that, external processing is required. For that matter, you probably need DSP on your mains to work with the subs from that direction, too.

Many amps these days basically throw in DSP capability for free. If you have a non-DSP amp, DSP functionality can be had for just a couple hundred dollars from a Behringer DCX-2496. Setting that up requires a little skill, or you can hire someone to help you once, then save those settings for use the rest of the time. For best performance of your many-thousand dollar rig, this is required no matter what subs or mains you end up with.

Like I already said, I never said I wasn't buying a processor. I was actually looking into getting that exact Behringer processor, if only for protection for any passive subs I end up getting.

And if you get 2 "weaker subs", you will be pushing them harder-meaning they will be more likely to break.

And the whole time you own them you will be getting output and low freq extension.

Do you also carry twice the top boxes-twice the amps-2 DJ mixers and so forth?

What if they break?

The only other "weaker sub" I'm looking into would in a pair be comperable in output to one TH-118. But that's besides the point, as I wouldn't push the weaker sub to make up for its downfall, as you're completely right that would increase it's chances in breaking.

It's ironic that you use those specific examples as I actually do have backups for those, haha! However I do see your point, but let me say this. If I'm running 4 tops and 2 subs, what happens if one sub or one top goes out? I still have sound, just not as loud. If I only have one sub and it goes out, I no longer have any bass at all.

Everything people have said about the inherent delay caused by the crossover filters and such is true.

But in the "ol days" we did not have delay to line up bevices-and i t worked just fine.

People often confuse "being perfectly acceptable" and "perfect".

In most cases if you run a full range cabinet with a TH118, all you have to is reverse the polarity of the TH118 and you will be perfectly fine.

It won't be "as good as" it could be-but you are probably 90% there.

Having delay available to you -and not have a measurement system and knowledge to use it, is only a guess.  Unless you are dealing with known quantities.

It is easy to get all "worried" about the little things that really don't matter to most people.

YES, it all the little things that ADD UP to a great sound, but only looking at one of them is not going to somehow magically make it sound better.

In my opinion-in your setup, I would not worry about it.

Flip the polarity and have a good day :)

HOWEVER, just be forwarned that "Flipping the polarity" is a SUGGESTION.  What is actually best depends on the rest of the system-how the crossover is setup and so forth.

The BEST way is to LISTEN to it with the polarity flipped and normal and then determine what give you the best "sound".

This applies to ANY sub/top combination.  Sometimes you will trade low freq for punch.  YOU have to make that call.

Maybe not a good analogy, but worrying about the delay time is like choosing a car depending on what oil it uses---------------

They all need it, and you can change types-it is not the end of the world or a reason to choose a different car.  Color is more important-------- :)

OK before the car guys get involved-YES I understand the differences in oil, but was trying to make a simple analogy-that was what came to mind.

I never doubted or argued with anyone about whether or not a crossover creates a phase shift. My point was that I don't know how to deal with the extra phase shift inherent in a tapped horn. However thanks to you, I now know that it's not nearly as big of an issue as I was making it out to be. I honestly didn't know whether or not the extra phase shift inherent in the box would make an audible difference for the worse. And all anyone was telling me was that "all subs need alignment". That doesn't help me! While I'm appreciative that I'm now aware of this information, I've never aligned bass reflex cabs to tops other than to make up for physical space differences and had no issues. So my main concern was that the EXTRA phase shift inherent in the Danley would be something I wouldn't know how to deal with, and would end up not sounding as good as a bass reflex cab.

Regardless of all of this, I would like to thank everyone with their help so far. It's very much appreciated.
Title: Re: Choosing the best sub for me
Post by: Lee Buckalew on May 29, 2015, 02:11:37 pm
You're right that they're very different options, but for my use case I think the Martin would be better suited. The system my company is looking to invest into would be used mainly for 500-1000 person EDM party type events. Basically small local EDM concerts.


Alex,
Given EDM the H3+ may be an O.K. choice.  I would suggest the H3T+ which can be tri-amped.  There are advantages to the eq and limiting that you can accomplish.  Limiting being a very good thing for EDM.

You are also going to want want more than a couple of anybodies 2x18 subs for EDM with the tops that you are considering.

As far as getting a hold of demo gear.  just call the rep to ask what would need to happen.

Lee
Title: Re: Choosing the best sub for me
Post by: Stephen Kirby on May 29, 2015, 02:32:59 pm
I never doubted or argued with anyone about whether or not a crossover creates a phase shift. My point was that I don't know how to deal with the extra phase shift inherent in a tapped horn.
Backing up a bit, if you admit that a front loaded system can be optimized by time aligning the tops and bottoms, then you simply do the same thing when one of the boxes has a longer path length.  What if you put KF850s over SRX728s?  It would be the other way around.

There are two common ways to do this.

The high end way is to run Smaart or something similar and tune the phase relationships precisely.

The other way is to run a test signal through both centered at the crossover frequency and adjust the delay in your DSP for maximum output (or with one side flipped in polarity for minimum output).  Not as sophisticated but gets you in the ballpark and prevents things being way off to the degree that the boxes are fighting each other.

This should be done with any combination of boxes.  Regardless of if they are from the same manufacturer or not, or use different technologies with different path lengths.
Title: Re: Choosing the best sub for me
Post by: Ivan Beaver on May 29, 2015, 02:38:34 pm

As for a mismatched system, trust me, I know! In February I used SoundBridge 7218SWX's along side EV ETX-35P's for mains and ZLX-12P's for front fills, and for years I'd used Behringer subs with no name MTX tops. The thing is, a matching system is a matching system. No matter how illogical it is, it's a matching system.

 My point was that I don't know how to deal with the extra phase shift inherent in a tapped horn.
I would love for somebody to explain to me how a matching system (other than physical size and flyware) works any better than different brand tops and subs.

It doesn't-as long as the freq bands overlap enough.

And if you are thinking that all products from a particular manufacturer will sound and perform the same-that is simply not the case.  They are all different.  And in some cases you would be BETTER OFF mixing brands.

You keep talking about the "extra phase shift" of the tapped horn.  Have you ever looked at the phase response/shift of a bass reflex/ported cabinet?  You do realize that the port freq are out of polarity with the freq from the front of the driver?  That is a lot of "phase shift" especially over a narrow freq range.

How do you deal with that?

I'm sorry, but if you are not delaying the subs to the tops, then you are not getting the best performance.  The FACT is that by using a normal crossover of either analog or digital, the lowpass filter adds delay/phase shift.

Your results may be "fine" but that does not mean they are as good as they could be if they were properly setup.

So what makes you think a Tapped horn is any different?

We do demos all the time with no delay on the subs and  the results are great.

Could it be better-sure. But the fact is you don't have to have delay to get a good result.

The wavelengths are so long at those freq- it is not as critical as it is with higher freq..

To me-this argument is taking one little piece of information and "blowing it up" into something bigger than it is, while completely ignoring the EXACT same problem with a different design.
Title: Re: Choosing the best sub for me
Post by: Alex Berry on May 29, 2015, 06:40:53 pm
Alex,
Given EDM the H3+ may be an O.K. choice.  I would suggest the H3T+ which can be tri-amped.  There are advantages to the eq and limiting that you can accomplish.  Limiting being a very good thing for EDM.

You are also going to want want more than a couple of anybodies 2x18 subs for EDM with the tops that you are considering.

As far as getting a hold of demo gear.  just call the rep to ask what would need to happen.

Lee

Thanks for the info! I'll definitely consider the H3T+. Have you heard the box? If so, do you have any impressions you could give me about it? I was looking into the WS218X specifically to compliment the H3. Probably something like 4 to start. With those duals being louder than the average dual, I think it would make for a good system.

Backing up a bit, if you admit that a front loaded system can be optimized by time aligning the tops and bottoms, then you simply do the same thing when one of the boxes has a longer path length.  What if you put KF850s over SRX728s?  It would be the other way around.

Yes but I didn't know specifically how to deal with it. I've never dealt with KF850s personally so if you hadn't explained how to properly align the boxes I wouldn't have known any better. I'm learning a lot from this thread, and am very appreciative! So I would like to thank you for the info!

I would love for somebody to explain to me how a matching system (other than physical size and flyware) works any better than different brand tops and subs.

It doesn't-as long as the freq bands overlap enough.

And if you are thinking that all products from a particular manufacturer will sound and perform the same-that is simply not the case.  They are all different.  And in some cases you would be BETTER OFF mixing brands.

Hey, I was agreeing with you! From a performace standpoint, I don't see any reason not to mix subs from one manufacturer with tops from another if they perform well together. The only thing is, and I really wouldn't know for sure, but I feel as if it would be harder to sell to a client a mismatched system than something like a full d&b system or a full L-Acoustics system. Although I don't know if that sort of thing would apply to me in my specific situation. Any thoughts would be helpful.

Quote
You keep talking about the "extra phase shift" of the tapped horn.  Have you ever looked at the phase response/shift of a bass reflex/ported cabinet?  You do realize that the port freq are out of polarity with the freq from the front of the driver?  That is a lot of "phase shift" especially over a narrow freq range.

I have, the sound coming from the port is 180 degrees out of phase from the sound radiating from the cone. My point was I didn't know that was something I had to deal with, and whether or not the extra phase shift from a tapped horn would be something I NEEDED to deal with. But thanks to you, I'm already aware that it's not an issue, so I thank you!

Quote
I'm sorry, but if you are not delaying the subs to the tops, then you are not getting the best performance.  The FACT is that by using a normal crossover of either analog or digital, the lowpass filter adds delay/phase shift.

I agree. Question. If you apply a lowpass to the subs (which causes phase shift) and a highpass at the same frequency to the tops (which I'm assuming also causes phase shift) wouldn't both the tops and the subs be shifted the same amount, therefore ceasing to be an issue? This is an honest question as I really don't know the answer.

Quote
Your results may be "fine" but that does not mean they are as good as they could be if they were properly setup.

So what makes you think a Tapped horn is any different?

The long horn length that the sound waves need to travel through made me think a tapped horn was different. But, again, thanks to you I now know this isn't an issue.

Quote
We do demos all the time with no delay on the subs and  the results are great.

Could it be better-sure. But the fact is you don't have to have delay to get a good result.

This is a huge deal to me, and I had no idea. This statement alone completely eases any concerns I had about "extra phase shift".

Quote
To me-this argument is taking one little piece of information and "blowing it up" into something bigger than it is, while completely ignoring the EXACT same problem with a different design.

I agree, but nobody was really understanding my concerns and I was totally uneducated to the fact. I am now educated, and we can move on!  ;D
Title: Re: Choosing the best sub for me
Post by: Ivan Beaver on May 29, 2015, 09:29:05 pm

I agree, but nobody was really understanding my concerns and I was totally uneducated to the fact. I am now educated, and we can move on!  ;D
I am not trying to be mean by my next comment.

You are NOT educated.  You have simple been exposed to a little (a very little bit) of what is really going on.

It gets a lot more complicated-even doing the basic alignments.

For example-in almost no case is the same crossover freq used for the subs and the tops.

Electrically this may make sense-but not ACOUSTICALLY. And THAT is what is important-NOT the electrical response.

When was the last time you saw a sub or a full range cabinet that had a flat response around your crossover freq?

Not in the pro world I assure you.

And do you run your subs as the same level as your mains?  If not (most subs are run hotter) then the acoustical crossover is VERY different that the electrical.

And when you are talking about "phase response"-what seat are you talking about?  With the mains in the air and the subs on the ground-as you move around  you will need different delays for different seats.

So there is no "perfect" alignment.  Only a perfect alignment at ONE (or maybe a couple)  seat-but not all.

Understanding what you CAN and (more importantly) CANNOT fix is VERY important.

I'm glad you are learning-but this is just the tip of the iceberg.

NEVER STOP LEARNING!!!!!!!!!!!
Title: Re: Choosing the best sub for me
Post by: Lee Buckalew on May 29, 2015, 11:02:31 pm
Thanks for the info! I'll definitely consider the H3T+. Have you heard the box? If so, do you have any impressions you could give me about it? I was looking into the WS218X specifically to compliment the H3. Probably something like 4 to start. With those duals being louder than the average dual, I think it would make for a good system.

I have not heard the H3 series of Blackline, I have used some of the Blackline series.  They would not be my first choice for live sound but for EDM they may do well. 

i do not know if they will sell them separately but for the cost of 4 WS218X and amplifiers and processing (depending on what amps and processing you are considering) you might be able to get DSX (or a smaller quantity of MSX) instead.  Self-powered, built in DSP.  That may be an option to consider.

I still would recommend hearing for yourself various options and seeing how they sound for what you need.  How they fit physically into your transport needs, look at what power is required for the various amplifier requirements, the pros and cons of each.  You can't get that from the brochures or spec sheets.

Lee
Title: Re: Choosing the best sub for me
Post by: Lyle Williams on May 30, 2015, 01:02:14 am
If you buy a powered system from a single vendor product line the alignment may be taken care of for you.

I went with etx18sp subs under etx tops because it was a simple setup with internal alignment and internal self protection.  Plug it together, hand it over to someone who will try and drive it too hard, and know that at the end of the show it won't be broken.

My passive rig was a techo's amusement ride.  Lets of fun knobs and settings, but it needed adult supervision.

The same inbuilt protection and alignment is available from most vendors.  When you try and go "best of breed" in a mixed system a whole bunch of responsibility falls to the operator.
Title: Re: Choosing the best sub for me
Post by: Lee Buckalew on May 30, 2015, 05:57:55 am
If you buy a powered system from a single vendor product line the alignment may be taken care of for you.

I went with etx18sp subs under etx tops because it was a simple setup with internal alignment and internal self protection.  Plug it together, hand it over to someone who will try and drive it too hard, and know that at the end of the show it won't be broken.

My passive rig was a techo's amusement ride.  Lets of fun knobs and settings, but it needed adult supervision.

The same inbuilt protection and alignment is available from most vendors.  When you try and go "best of breed" in a mixed system a whole bunch of responsibility falls to the operator.

There is no built in alignment of tops to subs because the two are located in physically separate and changeable spaces.

Lee
Title: Re: Choosing the best sub for me
Post by: Alex Berry on May 30, 2015, 12:28:30 pm
I am not trying to be mean by my next comment.

You are NOT educated.  You have simple been exposed to a little (a very little bit) of what is really going on.

It gets a lot more complicated-even doing the basic alignments.

For example-in almost no case is the same crossover freq used for the subs and the tops.

Electrically this may make sense-but not ACOUSTICALLY. And THAT is what is important-NOT the electrical response.

When was the last time you saw a sub or a full range cabinet that had a flat response around your crossover freq?

Not in the pro world I assure you.

And do you run your subs as the same level as your mains?  If not (most subs are run hotter) then the acoustical crossover is VERY different that the electrical.

And when you are talking about "phase response"-what seat are you talking about?  With the mains in the air and the subs on the ground-as you move around  you will need different delays for different seats.

So there is no "perfect" alignment.  Only a perfect alignment at ONE (or maybe a couple)  seat-but not all.

Understanding what you CAN and (more importantly) CANNOT fix is VERY important.

I'm glad you are learning-but this is just the tip of the iceberg.

NEVER STOP LEARNING!!!!!!!!!!!

Man, I really should have worded my response that you quoted differently. By my saying "I am now educated" I only meant that I am now educated to the fact that I shouldn't have been worrying as much about the "extra phase shift" as I was. Nothing more. I love this line of work, and I love learning as much about it as I possibly can. I was not trying to imply in any capacity that I was educated to all of the nuances involving phase response.

I have not heard the H3 series of Blackline, I have used some of the Blackline series.  They would not be my first choice for live sound but for EDM they may do well.

Any reasons as to why? Could you relate what you have heard to anything that I've heard (d&b J and V, QSC K, QSC KW, EV ETX, EV ZLX, JBL VRX, SoundBridge XYON)? I absolutely plan on demoing it, and am actually going to a show in July that has H3's and WS218X subs as their installed system, but I'd still love to get even the slightest of first impressions as I have absolutely no idea what to expect from the H3.

Quote
i do not know if they will sell them separately but for the cost of 4 WS218X and amplifiers and processing (depending on what amps and processing you are considering) you might be able to get DSX (or a smaller quantity of MSX) instead.  Self-powered, built in DSP.  That may be an option to consider.

I'm not really interested in getting anything from the MLA line, as I'm also relatively sure that Martin only sells MLA stuff as full, complete systems. Plus the WS218X will match perfectly with the WS18X.

Quote
I still would recommend hearing for yourself various options and seeing how they sound for what you need.  How they fit physically into your transport needs, look at what power is required for the various amplifier requirements, the pros and cons of each.  You can't get that from the brochures or spec sheets.

Like I already said, I absolutely plan on hearing all of this stuff before I buy any of it. I've already picked out amps and processing for everything (Crown XLS and Behringer DCX2496, regardless of people's feelings about XLS it fits perfectly into my budget, I already have one and love it, and they can be replaced down the road) and the pricing for the performance for the system as a whole seems very good to me.

If you buy a powered system from a single vendor product line the alignment may be taken care of for you.

I went with etx18sp subs under etx tops because it was a simple setup with internal alignment and internal self protection.  Plug it together, hand it over to someone who will try and drive it too hard, and know that at the end of the show it won't be broken.

I actually already have a pair of ETX-18SP subs and have used the 35P. I love the 35P for it's sound quality, but it doesn't stack up anywhere close to its adverstised SPL spec. Same goes for the 18SP, which is why I'm going to replace them most likely with the Martin WS18X (that or the Danley TH-118). I've already blown an 18SP somehow, and it just doesn't perform the way I was expecting it to. Plus it's not a scalable sub.

Quote
My passive rig was a techo's amusement ride.  Lets of fun knobs and settings, but it needed adult supervision.

The same inbuilt protection and alignment is available from most vendors.  When you try and go "best of breed" in a mixed system a whole bunch of responsibility falls to the operator.

You can get most of that protection with a passive system too with good outboard processing, which if I do end up going with a fully passive rig is exactly what I'm going to do. All of the limiters will be carefully set correctly (measuring the amps' output voltage with a sinewave input) and should perform just fine. No wondering or worrying if you're overpowering your speakers.
Title: Re: Choosing the best sub for me
Post by: Lyle Williams on May 30, 2015, 05:29:51 pm
There is no built in alignment of tops to subs because the two are located in physically separate and changeable spaces.

Lee

If the tops aren't near the subs, then the delay required can be dialed into the DSP in the sub or top.
Title: Re: Choosing the best sub for me
Post by: Lee Buckalew on May 30, 2015, 05:49:21 pm
If the tops aren't near the subs, then the delay required can be dialed into the DSP in the sub or top.

Exactly, the same thing that others have been saying in this thread.  Having same manufacturer subs and tops is of ZERO benefit sonically in terms of alignment. 
I was pointing out that there is no "internal" or "inbuilt alignment" as was referenced in your post.

Lee
Title: Re: Choosing the best sub for me
Post by: Lyle Williams on May 30, 2015, 05:57:04 pm
I actually already have a pair of ETX-18SP subs and have used the 35P. I love the 35P for it's sound quality, but it doesn't stack up anywhere close to its adverstised SPL spec. Same goes for the 18SP, which is why I'm going to replace them most likely with the Martin WS18X (that or the http://www.rcf.it/c/document_library/get_file?uuid=0ed178d6-1611-43d9-82c3-4fe7fe375997&groupId=216492Danley TH-118). I've already blown an 18SP somehow, and it just doesn't perform the way I was expecting it to. Plus it's not a scalable sub.

You can get most of that protection with a passive system too with good outboard processing, which if I do end up going with a fully passive rig is exactly what I'm going to do. All of the limiters will be carefully set correctly (measuring the amps' output voltage with a sinewave input) and should perform just fine. No wondering or worrying if you're overpowering your speakers.

Sorry to hear that you have blown an 18sp.  Did you kill a driver, or did the electronics break?

I find the etx18sp to be as loud or louder than comparable powered subs (PRX, KW,...)  There are certainly many other bigger boxes that get louder.  Some at LOT louder.  As with any rig, you need enough for your gig.

Setting limiter voltage protects you from overexcursion, but not from thermal failures. 

My point was that a coordinated system from a single vendor can have many issues looked after for you.

Title: Re: Choosing the best sub for me
Post by: Lyle Williams on May 30, 2015, 06:03:32 pm
Exactly, the same thing that others have been saying in this thread.  Having same manufacturer subs and tops is of ZERO benefit sonically in terms of alignment. 
I was pointing out that there is no "internal" or "inbuilt alignment" as was referenced in your post.

Lee

Top and sub meet each other at the crossover frequency when stacked.  If they are out of position by X meters, calculate this in milliseconds and dial it into a box.

Yes this can be done outboard with
Title: Re: Choosing the best sub for me
Post by: Lee Buckalew on May 30, 2015, 06:26:21 pm
Top and sub meet each other at the crossover frequency when stacked.  If they are out of position by X meters, calculate this in milliseconds and dial it into a box.

Yes this can be done outboard with

Incorrect, go back to Mac and Ivan's comments.  The distance converted to time is NOT the actual delay when measured whether stacked or not.  I know of no manufacturer who builds in delay like this between their powered subs and powered tops (there may be some that I don't know about) as there are usually multiple combinations of top model and sub model to choose from thereby making multiple combinations.  Additionally the proper crossover point, again, refer to the previous comments, is not a fixed frequency but varies based upon relative amplitude of the two pass bands.
You are correct that, in many cases self-powered systems take the many steps of properly matching system components, limiters, etc. out of the equation but alignment of subs to tops and configuration of crossover points (of the same) is not a fixed absolute in "matched" (or other) systems.

Lee
Title: Re: Choosing the best sub for me
Post by: Alex Berry on May 30, 2015, 06:39:31 pm
Sorry to hear that you have blown an 18sp.  Did you kill a driver, or did the electronics break?

Killed a driver. The sub wasn't outputting any sound yet the amp module was working perfectly. So as I was testing our other working sub, the blown sub was in close proximity and the bass coming from the working sub moved the cone of the blown sub, producing that obvious distortion that comes from a blown driver if it's not totally locked up. Luckily the amp module detects the short and mutes the amplifier output, minimizing the chances of any damage occurring to the amp module. I've heard of other people having their ETX subs/35P's blow also under normal use cases, so apparently it's not as unheard of as you would expect from something that's marketed to have such amazing protection features.

Quote
I find the etx18sp to be as loud or louder than comparable powered subs (PRX, KW,...)  There are certainly many other bigger boxes that get louder.  Some at LOT louder.  As with any rig, you need enough for your gig.

Absolutely. No arguments from me there. It definitely stacks up to its competition. I was just expecting it to beat the competition by a decent bit, and I'm no longer interested in anything from this level.

Quote
Setting limiter voltage protects you from overexcursion, but not from thermal failures.

Setting the limiter to limit at the continuous voltage rating of a speaker should protect it from thermal failures, although if you want to have bulletproof protection you could setup a second tier of limiting (long attack and release times) at an even lower threshold that would help deal with thermal problems.

Quote
My point was that a coordinated system from a single vendor can have many issues looked after for you.

Again, no arguments from me. It's just that that can get either very costly to fit what I need, or fit into my budget and not give me what I need.
Title: Re: Choosing the best sub for me
Post by: Ivan Beaver on May 30, 2015, 10:20:40 pm
Man, I really should have worded my response that you quoted differently. By my saying "I am now educated" I only meant that I am now educated to the fact that I shouldn't have been worrying as much about the "extra phase shift" as I was. Nothing more. I love this line of work, and I love learning as much about it as I possibly can. I was not trying to imply in any capacity that I was educated to all of the nuances involving phase response.


It all depends on what you mean "worrying about" the phase shift.

Today I was doing an alignment on a "BIG name brand" and popular line array and subs- all "matching" ;) ;)  That was speced by one of the "biggest names in the industry" and installed by a large install company.

No "second rate" stuff going on here.

The original installer and consultant made no attempt to "align" the subs to the tops-even though they were both flown side by side (a good thing).

By properly aligning the phase- I was able to get almost 6dB more out of them around crossover point.

This allowed me to shift the crossover points to reduce the freq range going to them (which means less power going to them), so there is a bit more headroom in both amplifier size and thermal capacity in both the subs and the tops.

SO YES-you CAN get more out of a system.  Do you need to "Worry"?  Well they were fine for a awhile-but I got a bit more out of it.

BTW these were reflex/ported subs and front loaded top boxes-NO horns-and they STILL benefited from a proper alignment.

BTW the crossover points were NOT the same between the boxes.

But the ONLY way you are going to get this type of advantage is through proper MEASUREMENT-not guess work.

Was it bad before hand?  NO.  Was it better afterwords? YES.

So it depends on what you consider "worry".

And if you are going to have to delay front loaded ported reflex boxes-then what is the difference between that and horn boxes.

They BOTH still need signal delay to get the best performance.
Title: Re: Choosing the best sub for me
Post by: Alex Berry on May 30, 2015, 10:46:12 pm
It all depends on what you mean "worrying about" the phase shift.

All I meant by worrying about the phase shift, was worrying that I needed to do something different to the tapped horn boxes that I wouldn't normally do to a bass reflex cab, which could mean the tapped horn subs wouldn't sound good in general at all unless I aligned the subs in a way that I didn't know how to do. All of this is irrelevant now, as you have alleviated my concerns.

I hate to hijack my own thread, but while I have you here I'd like to ask you some questions specifically about the SM80 (since I'm now aware that it's practically your baby) and the TH-118. Down the road, perhaps after the summer, my company is going to make an investment into a larger sound system than what we have now. The sound system would need to cover up to 1000 people comfortably in a room about this size or around there https://youtu.be/WCzj_ib0-5Y?t=8m7s (https://youtu.be/WCzj_ib0-5Y?t=8m7s) (you can get an idea for the size of the room in the video, but it's a high school gym). By comfortably I mean around 115dbA front row (perhaps with front fills), and around 100dbA at around halfway point to 2/3 of the way back. It would need to be able to play the same style of music in the video as well, specifically heavily compressed EDM. So we're talking some pretty abusive stuff here.

I'm seriously interested in the SM80 and the TH-118 to compliment after doing a bunch more research on them both. I've also read in other threads that you prefer to have 2-3 TH-118's for a loud rock show per SM80. Having a general idea how loud the TH-118 is (about as loud as 2 average dual 18s), this tells me that the SM80 is very very loud. Now you say this but in regards to live bands as your program material, and my style of music is very, very different. I'm looking to have 20-30db more bass than mid/high. So for instance if I'm sitting at a 115dbA front row, I'd really like to have at LEAST 135db in bass (40hz-100hz), preferably I'd like to be in the low 140's or even more.

So what I'm fully asking is would a pair of SM80's (with a proper sub compliment) be able to meet my requirements? Obviously I can just add more TH-118's if I need more sub volume, but it's not as easy as just adding more SM80's to get more mid/high volume.

I'd like to thank you again for all your help so far. I'm learning a lot from you, and am very appreciative!
Title: Re: Choosing the best sub for me
Post by: Stephen Kirby on May 31, 2015, 01:25:48 am
my style of music is very, very different. I'm looking to have 20-30db more bass than mid/high. So for instance if I'm sitting at a 115dbA front row, I'd really like to have at LEAST 135db in bass (40hz-100hz), preferably I'd like to be in the low 140's or even more.
So this plays to one of the things Ivan was talking about.  With the subs turned up that much more than the tops, the crossover is not going to be where you set the frequencies.  It's going to be higher.  Let's say you use an 18dB/octave crossover slope.  And for giggles let's say that your subs are 9dB hotter than your tops (20dB would obliterate the highs and you wouldn't hear much at all).  So now the intersection of those slopes is moved upwards in frequency, that is; at the point where the subs an tops are at the same level it's moved up an octave.  From say, 100Hz to 200Hz.  So you can actually move the sub LP down to get the intersection point where you want it.  Or change the slope to 24dB/octave or any number of other things.  Each of which will also introduce different amounts of phase shift.  So that thing I was telling you about playing a tone at the crossover point, you want to do it at the acoustic crossover.  The point where each band pass is outputting the same SPL.
Hopefully I've got this right.  It's been awhile since I played with it.
Title: Re: Choosing the best sub for me
Post by: Alex Berry on May 31, 2015, 01:45:29 am
So this plays to one of the things Ivan was talking about.  With the subs turned up that much more than the tops, the crossover is not going to be where you set the frequencies.  It's going to be higher.  Let's say you use an 18dB/octave crossover slope.  And for giggles let's say that your subs are 9dB hotter than your tops (20dB would obliterate the highs and you wouldn't hear much at all).  So now the intersection of those slopes is moved upwards in frequency, that is; at the point where the subs an tops are at the same level it's moved up an octave.  From say, 100Hz to 200Hz.  So you can actually move the sub LP down to get the intersection point where you want it.  Or change the slope to 24dB/octave or any number of other things.  Each of which will also introduce different amounts of phase shift.  So that thing I was telling you about playing a tone at the crossover point, you want to do it at the acoustic crossover.  The point where each band pass is outputting the same SPL.
Hopefully I've got this right.  It's been awhile since I played with it.

That's a fantastic point, and very helpful. I'll definitely take this into account in the future, thanks! And I'll have to disagree with your comment about 20db more bass than mid/high obliterating the highs. I've been in a club where the tops were sitting probably around 110dbA or so, and the bass was an easy 150db (unweighted), and I could easily hear the music. It was at a club with a d&b J series install (6 J8 and 2 J12 a side, but they weren't being pushed very much at all), but the artist playing had brought along their own compliment of 12 PK Sound CX800s. Was the bass modulating the music, absolutely. Was the system balanced? Hell no! But it was awesome, but that's beside the point. If my tops are sitting around 100dbA, and the bass at 120db (C or unweighted), I'd hardly consider the bass to be obliterating the highs. Perhaps I was not specific enough when I was giving my bass db level examples. I did mean them unweighted, not A weighted. I assumed Ivan wouldn't assume I usually like 135dbA of bass! Unweighted at 50hz that would be a 165! But I guess everyone knows what happens when you assume...
Title: Re: Choosing the best sub for me
Post by: John L Nobile on May 31, 2015, 01:56:58 am
That's a fantastic point, and very helpful. I'll definitely take this into account in the future, thanks! And I'll have to disagree with your comment about 20db more bass than mid/high obliterating the highs. I've been in a club where the tops were sitting probably around 110dbA or so, and the bass was an easy 150db (unweighted), and I could easily hear the music. It was at a club with a d&b J series install (6 J8 and 2 J12 a side, but they weren't being pushed very much at all), but the artist playing had brought along their own compliment of 12 PK Sound CX800s. Was the bass modulating the music, absolutely. Was the system balanced? Hell no! But it was awesome, but that's beside the point. If my tops are sitting around 100dbA, and the bass at 120db (C or unweighted), I'd hardly consider the bass to be obliterating the highs. Perhaps I was not specific enough when I was giving my bass db level examples. I did mean them unweighted, not A weighted. I assumed Ivan wouldn't assume I usually like 135dbA of bass! Unweighted at 50hz that would be a 165! But I guess everyone knows what happens when you assume...

Damn that's loud. I had to put earplugs in just to finish reading that post.
Title: Re: Choosing the best sub for me
Post by: Alex Berry on May 31, 2015, 02:18:05 am
Damn that's loud. I had to put earplugs in just to finish reading that post.

LOL! It really wasn't that bad, I've heard louder. It was very enveloping, and seems to be the norm for all of the EDM concerts I've been to so far.
Title: Re: Choosing the best sub for me
Post by: John L Nobile on May 31, 2015, 09:14:50 am
I'm having a really hard time with those DB numbers. How is it even possible to be in a room with that kind of volume? Disclaimer.... I've never been to an EDM event.
Title: Re: Choosing the best sub for me
Post by: Ivan Beaver on May 31, 2015, 09:28:00 am


I hate to hijack my own thread, but while I have you here I'd like to ask you some questions specifically about the SM80 (since I'm now aware that it's practically your baby) and the TH-118. Down the road, perhaps after the summer, my company is going to make an investment into a larger sound system than what we have now. The sound system would need to cover up to 1000 people comfortably in a room about this size or around there https://youtu.be/WCzj_ib0-5Y?t=8m7s (https://youtu.be/WCzj_ib0-5Y?t=8m7s) (you can get an idea for the size of the room in the video, but it's a high school gym). By comfortably I mean around 115dbA front row (perhaps with front fills), and around 100dbA at around halfway point to 2/3 of the way back. It would need to be able to play the same style of music in the video as well, specifically heavily compressed EDM. So we're talking some pretty abusive stuff here.

I'm seriously interested in the SM80 and the TH-118 to compliment after doing a bunch more research on them both. I've also read in other threads that you prefer to have 2-3 TH-118's for a loud rock show per SM80. Having a general idea how loud the TH-118 is (about as loud as 2 average dual 18s), this tells me that the SM80 is very very loud. Now you say this but in regards to live bands as your program material, and my style of music is very, very different. I'm looking to have 20-30db more bass than mid/high. So for instance if I'm sitting at a 115dbA front row, I'd really like to have at LEAST 135db in bass (40hz-100hz), preferably I'd like to be in the low 140's or even more.

So what I'm fully asking is would a pair of SM80's (with a proper sub compliment) be able to meet my requirements? Obviously I can just add more TH-118's if I need more sub volume, but it's not as easy as just adding more SM80's to get more mid/high volume.

I'd like to thank you again for all your help so far. I'm learning a lot from you, and am very appreciative!
Yes-having your subs 20dB hot (and sometimes even more) is not uncommon at all-It happens all the time at EDM shows

Here is a link to just about the setup/show you are talking about

Read the comments about more details of the event etc.  Before we had to turn it down (due to complaints from  4-5 miles away) we were around 124dB C at 100' outside. 

This video was after we turned it down.

https://www.facebook.com/ivan.beaver/videos/vb.100000581642030/1070611356301576/?type=2&theater

I am 100' from the speakers (that are 90 degrees from the DJ) with 1 SM80 per side.  We used 2 BC218s for subs.  So 2 tops and 2 bottoms and 2 amp channels total for the PA.

The BC218 (not the DBH218) goes lower than the TH118 and (within the TH118 operating range) it would take around 4 TH118s to equal a single BC218 and twice as many amp channels. 

Below 35Hz it will take more TH118s to equal a single BC218.

The TH118 is easier to move around, but the BC218s are really not bad-despite what people claim who have never moved them.  But steps are going to KILL you.

The BC218 gives you more "SPL per dollar" than the TH118.  So everything is a trade off.

Title: Re: Choosing the best sub for me
Post by: Ivan Beaver on May 31, 2015, 09:35:42 am
I'm having a really hard time with those DB numbers. How is it even possible to be in a room with that kind of volume? Disclaimer.... I've never been to an EDM event.
Those numbers are not out of bounds at all.

BASS rules when it comes to EDM shows.

Basically the full range cabinets are there to keep the bass from being so boring-------------------

The whole idea is to be "moved" by the subs, to feel the air getting sucked from your lungs and to be hit in the chest with a baseball bat and to make your "personal parts" tingle.

This was taken at an EDM show last year (the speakers are the front fills)

A sign maker saw some girls humping the speakers-so he made a sign.

One evening there was a couple that were actually "getting it on" with the girl pressed up against the main subs (BC415s).

She looked as if she was really enjoying the whole "experience".

https://www.facebook.com/photo.php?fbid=866711980024849&set=pb.100000581642030.-2207520000.1433079146.&type=3&theater
Title: Re: Choosing the best sub for me
Post by: John L Nobile on May 31, 2015, 09:50:21 am
Actually I did an EDM show about 6 years ago but I tried to flush it from my brain and it worked until now. :(
Over 700 drunken kids with a large S4 system. I remember counting 31 amps under the stage. I had earplugs in and it was still too loud for me. Guess I still didn't have it loud enough cause I never got called back.
But I got paid in cash.
Title: Re: Choosing the best sub for me
Post by: Alex Berry on May 31, 2015, 10:00:45 am
I'm having a really hard time with those DB numbers. How is it even possible to be in a room with that kind of volume? Disclaimer.... I've never been to an EDM event.

Perhaps this specification will help. I was close to being centered in the room, and close enough to the rail that the difference in overall volume between where I was and at the rail was absolutely no different. At the rail I was close enough to the subs I could reach out and touch them. I was taking the brute force of a 12 box dual 18 cluster run at full volume in a small club. Have you ever been front row at a big concert with a large sub array? If so, you'll probably have experienced close to the same numbers. Maybe not in sustained notes but most likely with something like a kick drum peak. Ultra Music Fest mainstage in Miami I believe has even higher numbers front row with their crazy huge sub array.

As for how is it possible to be in a room with that kind of volume, well you can't really see very well because it's vibrating your eyes to such a high degree. It fully modulates the music, so the system didn't have any semblance of balance or even necessarily sound good in the hifi sense. It's also so physically loud that it has a sort of therapeutic effect. I was getting very sore as the night drew to a close as I'm a small guy and I wasn't really pacing myself, and whenever the bass would cut out during a breakdown the pain in my legs and my stomach would really set in. As soon as the bass came back it would almost totally get rid of the pain.

Here is a link to just about the setup/show you are talking about

Read the comments about more details of the event etc.  Before we had to turn it down (due to complaints from  4-5 miles away) we were around 124dB C at 100' outside. 

The BC218 (not the DBH218) goes lower than the TH118 and (within the TH118 operating range) it would take around 4 TH118s to equal a single BC218 and twice as many amp channels. 

The TH118 is easier to move around, but the BC218s are really not bad-despite what people claim who have never moved them.  But steps are going to KILL you.

The BC218 gives you more "SPL per dollar" than the TH118.  So everything is a trade off.

Sweet baby Jesus those SM80's are loud! That would leave plenty of room to grow volume wise as currently most of the events I do don't need more than 2 TH118's for sub coverage.

I think for me the TH118 is the best solution due to it's mobility being the biggest deciding factor. Personally I would love to just get TH412s instead, but I wouldn't be able to move it by myself, and I usually have to traverse at least a couple of stairs.

A sign maker saw some girls humping the speakers-so he made a sign.

One evening there was a couple that were actually "getting it on" with the girl pressed up against the main subs (BC415s).

She looked as if she was really enjoying the whole "experience".

https://www.facebook.com/photo.php?fbid=866711980024849&set=pb.100000581642030.-2207520000.1433079146.&type=3&theater

Hahaha! It's a shame that Facebook link doesn't work, at least for me it doesn't.

Quote
Basically the full range cabinets are there to keep the bass from being so boring

While unfortunately this is the norm, I don't do this at the shows that I have control over the sound. While I do love the bass to be very loud, I don't like it to be so loud that it, as Stephen put it, obliterates the highs or is the main focus.

Actually I did an EDM show about 6 years ago but I tried to flush it from my brain and it worked until now. :(
Over 700 drunken kids with a large S4 system. I remember counting 31 amps under the stage. I had earplugs in and it was still too loud for me. Guess I still didn't have it loud enough cause I never got called back.
But I got paid in cash.

Most of the shows I've been to have actually been what I would consider to be WAY too loud in the mid/high department. For one example, I was at a show at Echostage in Washington, DC. Who knows why, but the front fills were pushed so far that vocalists in the songs sounded almost entirely like square waves. Who knows if it was the owner that liked that sound and thought it should be that way, or the FOH guy really didn't know what we was doing. But it seriously shouldn't have been that loud. At least a 120dbA where I was. The poor d&b V series cabs had to deal with way too much abuse that night.
Title: Re: Choosing the best sub for me
Post by: Alex Berry on May 31, 2015, 10:08:20 am
The BC218 (not the DBH218) goes lower than the TH118 and (within the TH118 operating range) it would take around 4 TH118s to equal a single BC218 and twice as many amp channels.

Sorry for the double post, but something else I just thought of. Do TH118s not gain 6db when you double the number of cabinets? Looking only at the continuous numbers and assuming the TH118 does gain 6db when doubling, it should really only take 2 TH118s to equal one BC218 in continuous ouput.
Title: Re: Choosing the best sub for me
Post by: Lee Buckalew on May 31, 2015, 10:13:08 am
Sorry for the double post, but something else I just thought of. Do TH118s not gain 6db when you double the number of cabinets? Looking only at the continuous numbers and assuming the TH118 does gain 6db when doubling, it should really only take 2 TH118s to equal one BC218 in continuous ouput.

No speakers, in real life, will gain 6dB/SPL by doubling the number of cabinets, at least not evenly across there full band pass.  The real numbers are more like 3dB/SPL.  Also, you have to double the amplifier power as well, not just add more subs.  Since most 2x18's are a 4 ohm setup you add significant amp channels to increase output by adding cabinets rather than going to more efficient cabinets.  More efficient speakers = fewer required amp channels and lower total power required to get the same (or even greater) SPL.

Lee
Title: Re: Choosing the best sub for me
Post by: Alex Berry on May 31, 2015, 10:19:15 am
No speakers, in real life, will gain 6dB/SPL by doubling the number of cabinets, at least not evenly across there full band pass.  The real numbers are more like 3dB/SPL. Also, you have to double the amplifier power as well, not just add more subs.

Wait, so assuming you double the number of subs and double the power, you'll only realistically see a 3db gain?

Quote
Since most 2x18's are a 4 ohm setup you add significant amp channels to increase output by adding cabinets rather than going to more efficient cabinets.  More efficient speakers = fewer required amp channels and lower total power required to get the same (or even greater) SPL.

I'd rather deal with the con of more amp channels to gain the pro of being able to easily move the individual subs around, and the additional pro of easily being able to scale down the system. Plus I just don't really need anything louder than a couple TH118s right now anyways.
Title: Re: Choosing the best sub for me
Post by: Lee Buckalew on May 31, 2015, 10:30:19 am
Wait, so assuming you double the number of subs and double the power, you'll only realistically see a 3db gain?

About 3dB/SPL gain across the operating frequency range, yes.

Lee
Title: Re: Choosing the best sub for me
Post by: Alex Berry on May 31, 2015, 10:31:17 am
About 3dB/SPL gain across the operating frequency range, yes.

Lee

Well that's a huge bummer. That just doubled the amount of subs I thought I needed.
Title: Re: Choosing the best sub for me
Post by: Lee Buckalew on May 31, 2015, 10:43:02 am
Well that's a huge bummer. That just doubled the amount of subs I thought I needed.

And could I draw your attention back to....😉

There are quite a number of things with sound that "in theory" should work a given way.  We don't like to remember what is actually required for the entire theory to hold true.  Much of the requirement can't happen in the real world with actual components.

Back to your comment.  Depending on how many cabinets this means that you ne to go to and how you would deploy them the addition of more cabinets can mean that you limit your coupling even more because the cabinet to cabinet to cabinet to cabinet, etc. spacing gets to be too great for coupling to occur.  This means that your real world increase of 3-4 dB/SPL for each doubling of cabinets and amplifier power has a finite limit of increase based upon your intended operating frequency range of the size of the array you create.

Lee
Title: Re: Choosing the best sub for me
Post by: Ivan Beaver on May 31, 2015, 10:54:56 am


I think for me the TH118 is the best solution due to it's mobility being the biggest deciding factor. Personally I would love to just get TH412s instead, but I wouldn't be able to move it by myself, and I usually have to traverse at least a couple of stairs.


The TH412 has a lot more output down below 35Hz, but is a bit larger to move around.  The TH118 goes up steps pretty easily
Title: Re: Choosing the best sub for me
Post by: Alex Berry on May 31, 2015, 10:59:42 am
And could I draw your attention back to....😉

There are quite a number of things with sound that "in theory" should work a given way.  We don't like to remember what is actually required for the entire theory to hold true.  Much of the requirement can't happen in the real world with actual components.

Back to your comment.  Depending on how many cabinets this means that you ne to go to and how you would deploy them the addition of more cabinets can mean that you limit your coupling even more because the cabinet to cabinet to cabinet to cabinet, etc. spacing gets to be too great for coupling to occur.  This means that your real world increase of 3-4 dB/SPL for each doubling of cabinets and amplifier power has a finite limit of increase based upon your intended operating frequency range of the size of the array you create.

Lee

Yea that's another great point. I was aware of that but selectively didn't like to think about it often. Semi off topic question, the bigger the array gets shouldn't the low end extension also increase? This being due to the fact that the far subs would only couple at lower frequencies? Lets say you have a cluster of 4 subs, cabinets being 21" wide. A sub left, B sub left center, C sub right center, D sub right. Subs A, B, and C would all couple at 80hz and below, and so would subs D, C, and B. But subs A and D would only couple at about 54hz and below. As you continued to add subs, wouldn't the low end extension of the system continue to increase due to this principle?

The TH412 has a lot more output down below 35Hz, but is a bit larger to move around.  The TH118 goes up steps pretty easily

Exactly why I would much rather use the TH412 but it's not exactly as practical as the TH118.
Title: Re: Choosing the best sub for me
Post by: Ivan Beaver on May 31, 2015, 11:09:11 am
Wait, so assuming you double the number of subs and double the power, you'll only realistically see a 3db gain?

I'd rather deal with the con of more amp channels to gain the pro of being able to easily move the individual subs around, and the additional pro of easily being able to scale down the system. Plus I just don't really need anything louder than a couple TH118s right now anyways.
If the subs are close together you WILL get 6dB pretty much across the freq range when you double the power and double the cabinets.  Sometimes you don't get as much towards the top end-(meaning 100-200Hz) but it should be at least 4-5dB.

I have MEASURED this many times and it is pretty much textbook.

Now as you move up in freq into the mid and high freq-yes-then you start to get less gain-because the sources are not close enough in physical distance in reference to the size of the wavelengths.

But at the low freq it does happen.

As with all things with speakers you HAVE to think in terms of wavelength physical size.
Title: Re: Choosing the best sub for me
Post by: Ivan Beaver on May 31, 2015, 11:29:13 am
Sorry for the double post, but something else I just thought of. Do TH118s not gain 6db when you double the number of cabinets? Looking only at the continuous numbers and assuming the TH118 does gain 6db when doubling, it should really only take 2 TH118s to equal one BC218 in continuous ouput.
Here is a good example of where simply looking at the "simple numbers" can get you in trouble.

To get the real answers you HAVE to look at a calibrated measured response.

The "continuous outputs" are based on sensitivity specs and power capacity and impedance.

But what is the sensitivity number based on?  For Danley-it is simply a number that I choose (not somebody in the marketing department) that I feel represents the overall average sensitivity.

But I could very easily choose a higher sensitivity and it could still be correct-because the speaker is able to produce that SPL at some freq.

HOWEVER-AND THIS IS A REALLY BIG BIG DEAL-that many manufacturers simply choose to IGNORE.

What does the -3dB or -10dB number come from??????????

It HAS to be -3 or -10 from "something"!!!!!!!!!!!!!!!!!!!!

The ONLY way it makes ANY sense is to have it TIED to the sensitivity number.  Therefore it is simply the freq at which the level is 3 (or10) dB down from the sensitivity.

OTHERWISE it is simply a number that (usually the marketing dept) thinks would look good on a spec sheet.

So what does this mean?  If we wanted a higher sensitivity number-then we ALSO MUST accept a higher -3dB number.  If we want a lower -3dB number-then we MUST ALSO accept a lower sensitivity number.

NO WAY AROUND IT-At least and being honest and providing numbers that actually MEAN something.

That is EXACTLY why we provide the ACTUAL MEASURED response graph for the user to come up with their own number.

Without that- you simply have NO IDEA where the numbers come from.

And if you don't believe me- go look at a variety of spec sheets (trust me I do it all the time) and "double check" the "simple numbers (sensitivity and -3dB freq) and see how they compare to the curve that they provide-ASSUMING they provide a curve.  It is become popular to not provide response curves-that way you don't have to "justify" your numbers".

There are MANY MANY manufacturers whos simple numbers simply DO NOT match their own response curves.

Our numbers come DIRECTLY from the response curve.

What does all this have to do with the original question?

Well it simply means that you cannot always easily compare the simple numbers when trying to determine how loud something will get.

It will vary with freq.

So once again- a "simple number" will often give a wrong answer.

I hope that helps a little in understanding how we get our numbers and what to look for when looking at other spec sheets.

DO NOT just look at the simple numbers-you can EASILY be fooled-and many people COUNT on that :(

Experience and real world is the REAL way to get the answers needed.

Go out and actually measure the products and see if they do what they say they do.  Put them side by side other products of "equal" specs and see how they stand up.  Not just in terms of SPL, but also sound quality-distortion etc.

I am not saying that others are lying-but in many cases they are NOT telling you the truth-at least in the way you are looking for.

Yes some manufacturers are much better and more accurate than others-but it is amazing to me how many can't even get their own spec sheets and data to agree with itself.

And this is not just at the "bottom" level-but also at the "top of the food chain" products.

But hey-if they can get you to buy a product based on the spec-then the marketing dept has done their job (even if they lied doing it). 

That is also the reason that some companies will not allow "official" side by side demos.  YES it happens-and fairly often.  Are they trying to hide something????????
Title: Re: Choosing the best sub for me
Post by: Ivan Beaver on May 31, 2015, 11:42:20 am
If the subs are close together you WILL get 6dB pretty much across the freq range when you double the power and double the cabinets.  Sometimes you don't get as much towards the top end-(meaning 100-200Hz) but it should be at least 4-5dB.

I have MEASURED this many times and it is pretty much textbook.

Now as you move up in freq into the mid and high freq-yes-then you start to get less gain-because the sources are not close enough in physical distance in reference to the size of the wavelengths.

But at the low freq it does happen.

As with all things with speakers you HAVE to think in terms of wavelength physical size.
And just to add to this-and further help clarify.

You will get the 6dB as long as the MEASUREMENT distance is relative to the size of the array of cabinets.

If you are up close and start adding cabinets further away you will NOT get the 6dB increase.

But at a further measurement distance you will get the 6dB.

I would say "just a guess here", that as long as the measurement distance is twice as far away than the closest to the furthest cabinet you should be 6dB.

So if you are 10M away-as long as the array is not wider than 5M you should see this

But if you are measuring at 1M and the array is 5M wide- you will not get the 6dB.

Once again "it depends" on what-where and how you are looking at things.

You can get very different results by simply "looking" at it differently.
Title: Re: Choosing the best sub for me
Post by: Alex Berry on May 31, 2015, 11:49:38 am
If the subs are close together you WILL get 6dB pretty much across the freq range when you double the power and double the cabinets.  Sometimes you don't get as much towards the top end-(meaning 100-200Hz) but it should be at least 4-5dB.

I have MEASURED this many times and it is pretty much textbook.

Now as you move up in freq into the mid and high freq-yes-then you start to get less gain-because the sources are not close enough in physical distance in reference to the size of the wavelengths.

But at the low freq it does happen.

As with all things with speakers you HAVE to think in terms of wavelength physical size.

Thank you! This is much more in line with what I thought was correct. I understood that coupling tops wont actually couple them due to the wavelengths being way too short (hence why the Synergy Horn is awesome cause the MF/HF drivers do couple), but that you could get extra sensitivity from coupling subs. I'm actually going to test this tonight as well, as I really just want to see definitively for myself.

Here is a good example of where simply looking at the "simple numbers" can get you in trouble.

To get the real answers you HAVE to look at a calibrated measured response.

The "continuous outputs" are based on sensitivity specs and power capacity and impedance.

But what is the sensitivity number based on?  For Danley-it is simply a number that I choose (not somebody in the marketing department) that I feel represents the overall average sensitivity.

I know, which is why I was relying on the "simple" numbers provided by you guys because I knew I could actually rely on them, or at least use them as a baseline.

Quote
But I could very easily choose a higher sensitivity and it could still be correct-because the speaker is able to produce that SPL at some freq.

HOWEVER-AND THIS IS A REALLY BIG BIG DEAL-that many manufacturers simply choose to IGNORE.

And if you don't believe me- go look at a variety of spec sheets (trust me I do it all the time) and "double check" the "simple numbers (sensitivity and -3dB freq) and see how they compare to the curve that they provide-ASSUMING they provide a curve.  It is become popular to not provide response curves-that way you don't have to "justify" your numbers".

There are MANY MANY manufacturers whos simple numbers simply DO NOT match their own response curves.

I know! It's extremely aggravating. I look at spec sheets all the time, and often derive my own "correct" SPL numbers from the frequency response, if it's provided.

Quote
Our numbers come DIRECTLY from the response curve.

What does all this have to do with the original question?

Well it simply means that you cannot always easily compare the simple numbers when trying to determine how loud something will get.

It will vary with freq.

I normally don't rely on the simple numbers across different companies, but with Danley I figured I could get a pretty good idea with just the simple numbers.

Quote
That is also the reason that some companies will not allow "official" side by side demos.  YES it happens-and fairly often.  Are they trying to hide something????????

This is hilarious, but not surprising by any means. It's like the story I read once about a "top tier" speaker manufacturer and why they choose not to make more efficient cabinets. Because they've already sold a ton of less efficient cabinets and if the clients need more volume, they can just buy more cabs!

And just to add to this-and further help clarify.

You will get the 6dB as long as the MEASUREMENT distance is relative to the size of the array of cabinets.

If you are up close and start adding cabinets further away you will NOT get the 6dB increase.

But at a further measurement distance you will get the 6dB.

I would say "just a guess here", that as long as the measurement distance is twice as far away than the closest to the furthest cabinet you should be 6dB.

So if you are 10M away-as long as the array is not wider than 5M you should see this

This also makes a lot of sense, and also all that really matters, to me at least. It's not that hard to get good bass levels close to the sub array.
Title: Re: Choosing the best sub for me
Post by: Alex Berry on May 31, 2015, 12:03:04 pm
Another hijack, how does the SM96 directly compare to the SM80? I realize the SM96 has much lower extension and isn't as loud, but if I just go by the "simple numbers"  ;) it should be able to handle everything from my smaller gigs to my bigger ones.
Title: Re: Choosing the best sub for me
Post by: Doug Fowler on May 31, 2015, 12:25:53 pm
LOL! It really wasn't that bad, I've heard louder. It was very enveloping, and seems to be the norm for all of the EDM concerts I've been to so far.

Your SPL expectations are way, way off.  A "standard" spec for EDM (meaning one used by the production manager of a huge EDM festival company) is 103 dBA in the center of the listening area, 124 dBC.  And that's pretty loud if it's a slow average.

Expectations of 140 dBC are, well, it won't happen nor should it.

In Miami in March, I saw thousands of happy campers swimming in glorious, deep clean 115 dbC bass, about 98-101 dBA for the rest of it.   With lots of compliments by DJs in the audiences, promoters and punters as well.  No dub, trap, or reggaeton though.

Title: Re: Choosing the best sub for me
Post by: Alex Berry on May 31, 2015, 12:30:52 pm
Your SPL expectations are way, way off.  A "standard" spec for EDM (meaning one used by the production manager of a huge EDM festival company) is 103 dBA in the center of the listening area, 124 dBC.  And that's pretty loud if it's a slow average.

Expectations of 140 dBC are, well, it won't happen nor should it.

In Miami in March, I saw thousands of happy campers swimming in glorious, deep clean 115 dbC bass, about 98-101 dBA for the rest of it.   With lots of compliments by DJs in the audiences, promoters and punters as well.  No dub, trap, or reggaeton though.

I could be very off, but I've been around car audio for a long time, so I know what a 150 sounds/feels like. I'm also talking about front row, essentially right up against the subs.
Title: Re: Choosing the best sub for me
Post by: Tim Weaver on May 31, 2015, 12:38:00 pm

And just to add to this-and further help clarify.

You will get the 6dB as long as the MEASUREMENT distance is relative to the size of the array of cabinets.

If you are up close and start adding cabinets further away you will NOT get the 6dB increase.

But at a further measurement distance you will get the 6dB.

I would say "just a guess here", that as long as the measurement distance is twice as far away than the closest to the furthest cabinet you should be 6dB.

So if you are 10M away-as long as the array is not wider than 5M you should see this

But if you are measuring at 1M and the array is 5M wide- you will not get the 6dB.

Once again "it depends" on what-where and how you are looking at things.

You can get very different results by simply "looking" at it differently.

And this is why I prefer to space out subs along the front of a stage. Assuming you have enough subs to go side-to-side at your preferred spacing.

This will allow the subs to couple and add at lower freqs, and be louder further away, but you aren't beating up on the front row as much. Since they are closer they "hear" fewer subs.

You can figure the spacing by using the 1/4 wavelength of the freq that you want additive coupling to start. For a large system I'll use the crossover freq (60 or 80 hz for Vertec for example) and set the subs a 1/4 wavelength apart at that freq.

So 1/4 wavelength of 60hz is 4.7 feet. Thats how much space I try to put between the subs.

Of course, do you make it center to center spacing? Or edge to edge? Its all about comprimises.
Title: Re: Choosing the best sub for me
Post by: Ivan Beaver on May 31, 2015, 12:45:31 pm
Another hijack, how does the SM96 directly compare to the SM80? I realize the SM96 has much lower extension and isn't as loud, but if I just go by the "simple numbers"  ;) it should be able to handle everything from my smaller gigs to my bigger ones.
The SM96 is more "hi-fi" sounding-but the SM80 goes way louder (even if it does not look like it on the spec sheet).

The components are simply much stronger.

Since you will be using subs-personally I would go with the SM80.

It is far better to have a cabinet that has plenty of "get up and go" left in it than to push a cabinet right to the edge.
Title: Re: Choosing the best sub for me
Post by: Doug Fowler on May 31, 2015, 12:51:59 pm
I could be very off, but I've been around car audio for a long time, so I know what a 150 sounds/feels like. I'm also talking about front row, essentially right up against the subs.

Recompile your cranial firmware and leave car audio out of the build.  Nothing about car audio applies here.  What happens in that tiny space is some other parallel universe in which our laws don't apply.

103 dbA listening area (max), 124 dbC (max), comfortable audience pleasing listening as I said: 100ish dBA, 115-120 dBC, adjust balance to taste depending on style.

For a few hundred people for EDM, 2x SM80 + 6x TH-118 is a banging hi fi system.  That is two amplifiers per side.  Power it correctly and enjoy.

I have no experience with the Martin solution, sorry.
Title: Re: Choosing the best sub for me
Post by: Ivan Beaver on May 31, 2015, 12:52:29 pm
And this is why I prefer to space out subs along the front of a stage. Assuming you have enough subs to go side-to-side at your preferred spacing.

This will allow the subs to couple and add at lower freqs, and be louder further away, but you aren't beating up on the front row as much. Since they are closer they "hear" fewer subs.

You can figure the spacing by using the 1/4 wavelength of the freq that you want additive coupling to start. For a large system I'll use the crossover freq (60 or 80 hz for Vertec for example) and set the subs a 1/4 wavelength apart at that freq.

So 1/4 wavelength of 60hz is 4.7 feet. Thats how much space I try to put between the subs.

Of course, do you make it center to center spacing? Or edge to edge? Its all about comprimises.
And of course the compromise with lining up the subs is that you start to narrow the horizontal pattern.

This could be good or bad-depending on the situation.

Yes you can delay the outer boxes-this can help, but it also hurts other areas.

And of course now you have nothing to "align  your tops to" since the bass is so spread out.

I do have a solution however.  All we need to do is to get the air temp up to something like 10,000 degrees.

Then the sound will greatly speed up, so it will act more like light and we would not have these timing problems.

All of these problem exist because air propagates so slowly through the air.

Then anybody could do it. you could just pile up speakers and party.

You might need a lot of water however-------------
Title: Re: Choosing the best sub for me
Post by: Alex Berry on May 31, 2015, 01:06:36 pm
Recompile your cranial firmware and leave car audio out of the build.  Nothing about car audio applies here.  What happens in that tiny space is some other parallel universe in which our laws don't apply.

103 dbA listening area (max), 124 dbC (max), comfortable audience pleasing listening as I said: 100ish dBA, 115-120 dBC, adjust balance to taste depending on style.

For a few hundred people for EDM, 2x SM80 + 6x TH-118 is a banging hi fi system.  That is two amplifiers per side.  Power it correctly and enjoy.

I have no experience with the Martin solution, sorry.

No offense, but AFAIK dB is dB. A 150 in a car, be it much MUCH easier to achieve than in a live sound setting, should still be the same as a 150 standing in front of the subs at a concert. I'm not saying I'm trying to achieve a 140 mid venue, the values you're suggesting are much closer to what I'm looking for. That rig you suggested is also pretty much exactly what I'm looking at. Although I do like the dispersion of the SM96 better, I'll simply have to demo both.

The SM96 is more "hi-fi" sounding-but the SM80 goes way louder (even if it does not look like it on the spec sheet).

The components are simply much stronger.

Since you will be using subs-personally I would go with the SM80.

It is far better to have a cabinet that has plenty of "get up and go" left in it than to push a cabinet right to the edge.

I agree that I'd rather have a cabinet that has plenty of headroom, but I think I like the 90x60 pattern better than the 80x80 pattern. Also price will end up being a factor. How many TH118s would you say it would take to keep up with a pair of SM96s? That should give me an idea of how much quieter the SM96 is than the SM80. Pretty much no matter which I end up going with will be much better and louder than what I have now and have used in the past.

I do have a solution however.  All we need to do is to get the air temp up to something like 10,000 degrees.

+10
Title: Re: Choosing the best sub for me
Post by: Doug Fowler on May 31, 2015, 01:15:09 pm
No offense, but AFAIK dB is dB. A 150 in a car, be it much MUCH easier to achieve than in a live sound setting, should still be the same as a 150 standing in front of the subs at a concert. I'm not saying I'm trying to achieve a 140 mid venue, the values you're suggesting are much closer to what I'm looking for. That rig you suggested is also pretty much exactly what I'm looking at. Although I do like the dispersion of the SM96 better, I'll simply have to demo both.

I agree that I'd rather have a cabinet that has plenty of headroom, but I think I like the 90x60 pattern better than the 80x80 pattern. Also price will end up being a factor. How many TH118s would you say it would take to keep up with a pair of SM96s? That should give me an idea of how much quieter the SM96 is than the SM80. Pretty much no matter which I end up going with will be much better and louder than what I have now and have used in the past.

+10

Where are you located?
Title: Re: Choosing the best sub for me
Post by: Alex Berry on May 31, 2015, 01:16:11 pm
Where are you located?

Central Pennsylvania.
Title: Re: Choosing the best sub for me
Post by: Lee Buckalew on May 31, 2015, 01:43:12 pm
Thank you! This is much more in line with what I thought was correct. I understood that coupling tops wont actually couple them due to the wavelengths being way too short (hence why the Synergy Horn is awesome cause the MF/HF drivers do couple), but that you could get extra sensitivity from coupling subs. I'm actually going to test this tonight as well, as I really just want to see definitively for myself.

I never said you could never achieve an increase of 6 dB/SPL but, in a portable situation, with configurations differing, both in speaker layout and audience relative to speakers, it is rare to get an even increase across the whole frequency range and have that evenly throughout the whole space.  I never figure on an increase of 6 I figure on 4 which I have found to be more repeatable in various layouts.

Lee
Title: Re: Choosing the best sub for me
Post by: Alex Berry on May 31, 2015, 01:47:37 pm
I never said you could never achieve an increase of 6 dB/SPL but, in a portable situation, with configurations differing, both in speaker layout and audience relative to speakers, it is rare to get an even increase across the whole frequency range and have that evenly throughout the whole space.  I never figure on an increase of 6 I figure on 4 which I have found to be more repeatable in various layouts.

Lee

I'm more concerned with "if I put two subs together will I gain 6db or 3db". As you state, there are many other variables that will potentially prevent some of the coverage area from seeing the extra 6db, but as long as I haven't been doing the basic math totally wrong all this time I'm fine with assuming that when I couple two subs, I gain 6db.
Title: Re: Choosing the best sub for me
Post by: Lee Buckalew on May 31, 2015, 02:08:48 pm
I'm more concerned with "if I put two subs together will I gain 6db or 3db". As you state, there are many other variables that will potentially prevent some of the coverage area from seeing the extra 6db, but as long as I haven't been doing the basic math totally wrong all this time I'm fine with assuming that when I couple two subs, I gain 6db.

It's fine if that's how you choose to look at it.  I, on the other hand, choose to plan on a 4dB/SPL increase because I can actually achieve it in most cases.  I may even be able to achieve better than 4 but I can't always get better.  Assuming a 6 dB/SPL increase is a bad idea, in my opinion, because it can not always be achieved.

Edited in:  you will also experience power compression due to heating of the drivers, especially with EDM.  This will also limit your output capability to below manufacturers rated output.

Lee
Title: Re: Choosing the best sub for me
Post by: Alex Berry on May 31, 2015, 02:33:23 pm
It's fine if that's how you choose to look at it.  I, on the other hand, choose to plan on a 4dB/SPL increase because I can actually achieve it in most cases.  I may even be able to achieve better than 4 but I can't always get better.  Assuming a 6 dB/SPL increase is a bad idea, in my opinion, because it can not always be achieved.

Lee

And that's a better way to do it, but since I'm already used to a standard of 6db change, changing that could throw off all of my mental assumptions for the worse. I'm just using it to get a very rough idea of how loud a system will be. Nothing specific or meant to be relied upon.
Title: Re: Choosing the best sub for me
Post by: Ivan Beaver on May 31, 2015, 03:18:39 pm
It's fine if that's how you choose to look at it.  I, on the other hand, choose to plan on a 4dB/SPL increase because I can actually achieve it in most cases.  I may even be able to achieve better than 4 but I can't always get better.  Assuming a 6 dB/SPL increase is a bad idea, in my opinion, because it can not always be achieved.

Edited in:  you will also experience power compression due to heating of the drivers, especially with EDM.  This will also limit your output capability to below manufacturers rated output.

Lee
I would argue that given the small number of subs that are being talked about, if you put them together you could easily plan on a 6dB increase in SPL below 100hz.

Spreading them out is a different story.  But then we are back to the whole distance of the listener (measurement) vs spacing of the subs thing
Title: Re: Choosing the best sub for me
Post by: Ivan Beaver on May 31, 2015, 03:22:23 pm
No offense, but AFAIK dB is dB. A 150 in a car, be it much MUCH easier to achieve than in a live sound setting, should still be the same as a 150 standing in front of the subs at a concert.
It is simply the "PRESSURE" of the air that is being "compressed".

In a small closed environment (such as a car) it is not that hard to get high SPL numbers.  Heck all you have to do is compress the roof a bit and get SPL numbers.

Now what it feels like and what it sounds like, can be very different things.

Such as with a butt shaker.  You kinda get the "sense" that there is a lot of bass (buy your body telling you it is shaking) but the actual SPL is much lower.
Title: Re: Choosing the best sub for me
Post by: Ivan Beaver on May 31, 2015, 03:36:10 pm

I agree that I'd rather have a cabinet that has plenty of headroom, but I think I like the 90x60 pattern better than the 80x80 pattern. Also price will end up being a factor. How many TH118s would you say it would take to keep up with a pair of SM96s? That should give me an idea of how much quieter the SM96 is than the SM80. Pretty much no matter which I end up going with will be much better and louder than what I have now and have used in the past.


You ALSO have to consider that the rated patterns of ALL loudspeakers DOES NOT mean that they actually have that pattern across their entire freq range.

And even then the actual pattern changes with freq-some more than others.

In many cases the pattern is only for 2, maybe 3 octaves.  It takes LARGE horns (something that most cabinets are missing) to be able to control freq down below even 1Khz.

But most don't want to discuss that ;)

But let's assume the pattern is "correct".

A 90 wide pattern is only 5 degrees wider on each side.  Is that enough to "make or break" the gig?  Especially for EDM?  I doubt it.

When people say "it takes x amount of subs to "keep up" with a particular box-"that is only a wild rough idea of a guess.

It comes down to how much louder the subs are running than top box.

Is it 15dB? or say 21dB?  The difference is TWICE the amount of subs.

So 2 subs vs 3 subs is around a 3dB difference.

And when you start factoring in things like "exactly what does the power handling really mean" and understand that it is simply a shaped test signal that may not have anything to do with your particular music, then it starts to get even more complicated.

Your music may put more or less strain on the cabinet than the test signal. 

If you were doing what many would consider "quality music", then the Sm96 could be a better choice (assuming it would go loud enough for the size audience you are trying to cover).

But for most "overall" live and party type events, the SM80 would be my choice.

For what it is worth the SM80 is a tad less expensive than the Sm96, but not enough to make one choose the other over price.  About a 3% difference-retail.  But I do not discuss specific prices-not my job.

The SM80 sits better on a pole also.
Title: Re: Choosing the best sub for me
Post by: Ivan Beaver on May 31, 2015, 03:42:20 pm
No offense, but AFAIK dB is dB.
The term dB has absolutely NO value.

All it is is a RATIO between 2 know values.  dB could be used to describe distance-voltage-power-pressure etc.

Since it is a ratio-that is the beautiful thing about it, a 6dB increase in voltage is the same as a 6dB increase in power.  So double the voltage = 4 times the power.

In SPL you are comparing a measured value against the "reference value" of 0dB and it simply tells you how much louder your signal is than 0.

0 does NOT mean no sound.  In fact you can have negative SPL numbers if the sound is quieter than the reference
Title: Re: Choosing the best sub for me
Post by: Alex Berry on May 31, 2015, 10:30:55 pm
It is simply the "PRESSURE" of the air that is being "compressed".

In a small closed environment (such as a car) it is not that hard to get high SPL numbers.  Heck all you have to do is compress the roof a bit and get SPL numbers.

Now what it feels like and what it sounds like, can be very different things.

Such as with a butt shaker.  You kinda get the "sense" that there is a lot of bass (buy your body telling you it is shaking) but the actual SPL is much lower.

Agreed totally. Although in a car environment, they almost always demo their systems with a bunch of windows open to let the system "breathe". Not necessarily to help cool the drivers, but it allows for a decent SPL gain and lower extension. And it provides for more of a loud experience than a pressurized experience. I've also heard enough systems at 150db or above that I have a pretty good grasp of how loud it is.

You ALSO have to consider that the rated patterns of ALL loudspeakers DOES NOT mean that they actually have that pattern across their entire freq range.

Yes but Danley is better at this than most, as far as I'm aware.

Quote
But let's assume the pattern is "correct".

A 90 wide pattern is only 5 degrees wider on each side.  Is that enough to "make or break" the gig?  Especially for EDM?  I doubt it.

Absolutely not, I'm more interested in the 60 degrees of vertical dispersion in the SM96 vs the 80 degrees in the SM80. Although how much of a difference this will make practically, I'm not sure.

Quote
When people say "it takes x amount of subs to "keep up" with a particular box-"that is only a wild rough idea of a guess.

You've said before that you like 2-3 TH118s per SM80 for a loud rock show, and that you ran 2 BC218's with 2 SM80s and that a single BC218 is about equivalent to 4 TH118s. I know it's not this simple, but I'm only looking for a rough estimate. Given this sub to top ratio with the SM80, lets transfer whatever that ratio is over to the SM96. Then, using that ratio, how many TH118s would it take to "keep up" with an SM96?

Quote
If you were doing what many would consider "quality music", then the Sm96 could be a better choice (assuming it would go loud enough for the size audience you are trying to cover).

But for most "overall" live and party type events, the SM80 would be my choice.

Lets make this real simple. I was able to cover my target venue at around my target SPL at about 1/3 capacity of the venue with two EV ETX-35P's with ZLX-12P's for front fills (we're leaving subs out of this example). The front fills are basically not important because they weren't placed high enough to cover more than the very front row or two. I've measured the 35P on music to average around 118dbA in a very light limit. You can, however, push the 35P heavier into limit without any problems. I did do this for the event of which the pair was able to cover well, so lets say I gained an extra 2db from pushing it further into limit. This gives me around a measured 120dbA on music (yes I know the specific music is a huge variable but lets not worry about that right now, we're only dealing with rough estimates here). Roughly and practically, how much louder is the SM96 than the EV ETX-35P? If it is in real world situations actually able to produce 124db continuous, then it will be a good cabinet for me. Although, with it being around the same price as an SM80, the SM80 might be a better route.

The term dB has absolutely NO value.

All it is is a RATIO between 2 know values.  dB could be used to describe distance-voltage-power-pressure etc.

Since it is a ratio-that is the beautiful thing about it, a 6dB increase in voltage is the same as a 6dB increase in power.  So double the voltage = 4 times the power.

In SPL you are comparing a measured value against the "reference value" of 0dB and it simply tells you how much louder your signal is than 0.

0 does NOT mean no sound.  In fact you can have negative SPL numbers if the sound is quieter than the reference

I know, I should have stated db SPL, but I assumed Doug knew I was talking about db SPL without me needing to specify it.
Title: Re: Choosing the best sub for me
Post by: Lee Buckalew on May 31, 2015, 10:51:23 pm
...lower extension.

You have mentioned in earlier posts of this thread the idea of getting lower frequency extension by adding subs.  There are a few different posts here if you search that show that this really does not hold to be true.  If you want response to a certain frequency get subs that can do it, don't rely on adding more subs to gain additional frequency response.

Lee
Title: Re: Choosing the best sub for me
Post by: Alex Berry on May 31, 2015, 10:59:57 pm
You have mentioned in earlier posts of this thread the idea of getting lower frequency extension by adding subs.  There are a few different posts here if you search that show that this really does not hold to be true.  If you want response to a certain frequency get subs that can do it, don't rely on adding more subs to gain additional frequency response.

Lee

Oh no, I'm not relying on adding subs to provide lower extension. I was simply wondering whether or not adding subs did lower the overall capable frequency response of the system due to subs that are further apart only coupling at lower frequencies. If realistically this isn't true, then whatever, it's not a concern. If, however, it is true then that's awesome and welcomed. Either way, I'm just curious.
Title: Re: Choosing the best sub for me
Post by: Ivan Beaver on June 01, 2015, 07:33:24 am


Absolutely not, I'm more interested in the 60 degrees of vertical dispersion in the SM96 vs the 80 degrees in the SM80. Although how much of a difference this will make practically, I'm not sure.

You've said before that you like 2-3 TH118s per SM80 for a loud rock show, and that you ran 2 BC218's with 2 SM80s and that a single BC218 is about equivalent to 4 TH118s. I know it's not this simple, but I'm only looking for a rough estimate. Given this sub to top ratio with the SM80, lets transfer whatever that ratio is over to the SM96. Then, using that ratio, how many TH118s would it take to "keep up" with an SM96?

 Roughly and practically, how much louder is the SM96 than the EV ETX-35P? If it is in real world situations actually able to produce 124db continuous, then it will be a good cabinet for me. Although, with it being around the same price as an SM80, the SM80 might be a better route.


As usual there is A LOT more than "simple numbers" will tell you.

The SM80 will have pattern control to a lower freq than the SM96 in the  60 degree coverage.

This is for 2 reasons.  First the horn on the SM80 is larger.

Second since the pattern is wider on the Sm80-for a given size horn the wider pattern will have control down lower-it will naturally control lower.

So while you are getting 60 degrees in the mid and high freq-it starts to get wider as you go lower, while the Sm80 is still controlling the pattern.

There is no "magic number" for subs to tops.

You really have to look at each situation.  In the particular situation that we used the BC218s-the main reason we used them was due to pattern control/rear rejection on the back side.

There was a neighborhood behind the speaker position (the reason we placed the speakers where we did), and we wanted the most rear rejection.

Also we wanted deeper extension since it was an EDM event.

Plus they were available-so why not :)

And they may not be "overkill" for a rock band.

As far as moving them around-we had a lot of college guys who were very egar to help-so I did not have to touch a thing. :)

How many TH118s to SM96?  There is no simple answer-  The real answer lies in how much louder the subs are run-and different people like different amounts of bass.  So I would say the answer is somewhere between 1 and 4 subs to each SM96-depending-----------

For a standard rock band that was not to loud-1 or 2.

But I would not choose the SM96 for a rock band in a club.

Regarding the "continuous" output RATING and the  REAL WORLD-very often they are different.

I know people want them to be the same-but the simple reason is that the test signal is not the same.

The standard test signal has a crest factor of 6dB.  Standard music (even pretty compressed) has a crest factor of 10-15dB.

So if you use the peak rating of the loudspeaker-you can easily see that the "real music continuous" is going to be 4-10dB lower.

I use -10dB as a "standard guess-ta-mate" to get realistic levels that could be expected to the listener during show time.

The EV will have a good bit more bass than the the SM80-no question.

It is hard to make comparisons without real data-but the SM80 has a horn loaded 12" mid-and the SM96 is a 5", as compared to a 6.5" (which is also horn loaded) on the EV.  I have no way to compare the quality of the drivers-other than size.

I don't know if the 1.25" HF driver is exit size or voice coil size.  The SM80 has a 3" voice coil and the SM96 has a 1.5" diaphragm.  Again no other way to compare except size.

I won't make any other comments about performance specs on the EV box. and how they relate to each other.  I leave that to others to figure out.
Title: Re: Choosing the best sub for me
Post by: David Morison on June 01, 2015, 09:26:59 am
Oh no, I'm not relying on adding subs to provide lower extension. I was simply wondering whether or not adding subs did lower the overall capable frequency response of the system due to subs that are further apart only coupling at lower frequencies. If realistically this isn't true, then whatever, it's not a concern. If, however, it is true then that's awesome and welcomed. Either way, I'm just curious.

It won't change the actual ability of each box to produce more level at the bottom end of it's response, no, but if they couple less well at the upper end of their range, then subjectively you might think they sound deeper due to there being less upper bass present.
HTH,
David.
Title: Re: Choosing the best sub for me
Post by: Alex Berry on June 01, 2015, 11:47:23 am
As usual there is A LOT more than "simple numbers" will tell you.

The SM80 will have pattern control to a lower freq than the SM96 in the  60 degree coverage.

This is for 2 reasons.  First the horn on the SM80 is larger.

Second since the pattern is wider on the Sm80-for a given size horn the wider pattern will have control down lower-it will naturally control lower.

So while you are getting 60 degrees in the mid and high freq-it starts to get wider as you go lower, while the Sm80 is still controlling the pattern.

This is a fantastic point, and will be a big deciding factor for me.

Quote
There is no "magic number" for subs to tops.

You really have to look at each situation.  In the particular situation that we used the BC218s-the main reason we used them was due to pattern control/rear rejection on the back side.

There was a neighborhood behind the speaker position (the reason we placed the speakers where we did), and we wanted the most rear rejection.

Makes a lot of sense, but I was referring to them more in terms of their output and not how directional they are.

Quote
Also we wanted deeper extension since it was an EDM event.

Plus they were available-so why not :)

+1 this!

Quote
For a standard rock band that was not to loud-1 or 2.

But I would not choose the SM96 for a rock band in a club.

Ok, thanks! This is more of what I was looking for.

Quote
So if you use the peak rating of the loudspeaker-you can easily see that the "real music continuous" is going to be 4-10dB lower.

I use -10dB as a "standard guess-ta-mate" to get realistic levels that could be expected to the listener during show time.

This is also helpful, thanks.

Quote
The EV will have a good bit more bass than the the SM80-no question.

It is hard to make comparisons without real data-but the SM80 has a horn loaded 12" mid-and the SM96 is a 5", as compared to a 6.5" (which is also horn loaded) on the EV.  I have no way to compare the quality of the drivers-other than size.

I don't know if the 1.25" HF driver is exit size or voice coil size.  The SM80 has a 3" voice coil and the SM96 has a 1.5" diaphragm.  Again no other way to compare except size.

I won't make any other comments about performance specs on the EV box. and how they relate to each other.  I leave that to others to figure out.

I ran the EV's crossed at 100hz, so bass wasn't a concern of mine from the EV's. At that gig I actually ran them with 8 Soundbridge 7218SWX subs powered by Powersoft K10 amps. I was only running about 125 watts into each sub, and was getting around a 135-140 10-20 feet away from the subs.

I can say the 35P's are some of the cleanest, best sounding speakers I've ever heard. I can only compare them in SQ to d&b J series boxes. The HF driver in the 35P is a DH-3B, and the DH-3 is a 1.25" diaphragm, so I think the DH-3B is as well. Unfortunately EV hasn't posted anything about the DH-3B.

Basically, I'm now more interested in the SM80 anyways. If it can do more than a 120dbA at 1m continuous on music, it'll beat out the 35P. For the price it better!
Title: Re: Choosing the best sub for me
Post by: Jacob Shaw on June 18, 2015, 02:43:08 am
I would like to comment on the debate about the front loaded subs be horn loaded subs and latency.  It is my understanding that any time Sound waves of the same frequency are coming from two different locations and they begin to occupy the same space they are either going to "sum" or they are going to "cancel".  Of course there is a hypothetical scenario where it is exactly 90 degrees out of phase and it does neither, but that has about the same chances of happening as a pubic hair being exactly .5 mm thick (it is more likely to be .49855531753mm thick or some other astronomical decimal).  "Sum" = <90 degrees out of phase= an increase in spl.  "Cancellation"= >90 degrees and <170 degrees out of phase= a decrease in spl. 
     That being said, if you have front loaded reflex subs and mains with front loaded mid drivers ground stacked with the fronts lined up crossed over at say 100hz they WILL "sum" at the bandwidth that they are producing in common.  I don't believe to be a situation where "it depends",  they will sum, period.  Summing is better than canceling because if you have cancellation and you need more 100hz you won't get it no matter how much you boost that band.  If the drivers are at least "summing" then you can at least correct the response with eq.  This is why you see a lot of powered subs with a 180 degree phase switch, if you find that you have cancellation you can flip this switch and although you won't be perfectly in phase it will at least get you "summing".  Of course if you have the time and resources to get you system in phase as much as possible this is ideal and will minimize the amount of eq nessicary (important if you are Eqing with a driverack with limited bands of eq).
Title: Re: Choosing the best sub for me
Post by: Jacob Shaw on June 18, 2015, 02:50:38 am
I will say that the Martins are sweet.  I went to u-street hall to here them and was thoroughly impressed.  As reflex boxes go I would say that they are one of the most environmentally friendly options as the drivers get loud as hell with only 500w.
Title: Re: Choosing the best sub for me
Post by: Ivan Beaver on June 18, 2015, 07:12:41 am
I would like to comment on the debate about the front loaded subs be horn loaded subs and latency.  It is my understanding that any time Sound waves of the same frequency are coming from two different locations and they begin to occupy the same space they are either going to "sum" or they are going to "cancel".  Of course there is a hypothetical scenario where it is exactly 90 degrees out of phase and it does neither, but that has about the same chances of happening as a pubic hair being exactly .5 mm thick (it is more likely to be .49855531753mm thick or some other astronomical decimal).  "Sum" = <90 degrees out of phase= an increase in spl.  "Cancellation"= >90 degrees and <170 degrees out of phase= a decrease in spl. 
     That being said, if you have front loaded reflex subs and mains with front loaded mid drivers ground stacked with the fronts lined up crossed over at say 100hz they WILL "sum" at the bandwidth that they are producing in common.  I don't believe to be a situation where "it depends",  they will sum, period.  Summing is better than canceling because if you have cancellation and you need more 100hz you won't get it no matter how much you boost that band.  If the drivers are at least "summing" then you can at least correct the response with eq.  This is why you see a lot of powered subs with a 180 degree phase switch, if you find that you have cancellation you can flip this switch and although you won't be perfectly in phase it will at least get you "summing".  Of course if you have the time and resources to get you system in phase as much as possible this is ideal and will minimize the amount of eq nessicary (important if you are Eqing with a driverack with limited bands of eq).
The issue is the PHASE response.

The problems start when they are in phase at some freq and not so "inphase" at other freq.

So some freq will be louder-but others will be quieter. 

So do they sum?  Well it depends on what freq you are looking at.

You HAVE to look across the entire intended operating freq range-NOT just a single freq or two.

Phase is VERY VERY important-in many different ways.  Yet most people just want to forget about it-probably because they don't understand it.

It gets to be a real problem when modeling loudspeakers.  Some manufacturers turn off the phase response in the data they submit for the modeling programs.  This means the models will not show all the interference THAT DOES HAPPEN IN THE REAL WORLD, but it look pretty in the coverage in the model-which IS NOT the real world.

You HAVE to look deeper to get the real answer.
Title: Re: Choosing the best sub for me
Post by: Stephen Kirby on June 18, 2015, 01:16:51 pm
     That being said, if you have front loaded reflex subs and mains with front loaded mid drivers ground stacked with the fronts lined up crossed over at say 100hz they WILL "sum" at the bandwidth that they are producing in common.  I don't believe to be a situation where "it depends",  they will sum, period.

As has been mentioned above, all crossovers and other filter networks (eq's) will introduce phase shift.  To varying degrees depending on their topology.  So physical alignment has no guarantee of phase alignment.  My quasi tapped horn Cubo Subs (which have the driver in the horn throat) need 6ms delay in the tops with the voice coils physically vertically aligned and using 24dB/8va LR crossovers.
Title: Re: Choosing the best phase for me
Post by: Mac Kerr on June 18, 2015, 03:03:42 pm
That being said, if you have front loaded reflex subs and mains with front loaded mid drivers ground stacked with the fronts lined up crossed over at say 100hz they WILL "sum" at the bandwidth that they are producing in common.  I don't believe to be a situation where "it depends",  they will sum, period.

Sadly, you are not correct. As has been explained repeatedly, the crossover that low passes the sub will cause phase shift which will appear to a time only analysis as delay. The crossover that high passes the mains will not induce a compensating phase shift.

Even if there is no electrical or electronic crossover involved there is no guarantee that the phase response of the drivers will be matching. Optimizing the phase of both systems throughout the crossover range requires measurement and correction.

Mac
Title: Re: Choosing the best sub for me
Post by: Jacob Shaw on June 18, 2015, 06:53:04 pm
Guys, guys, you do not have to have phase alignment for the speakers to sum, it just has to be close enough to not cancel.  And I don't see why you would need to look at the entire operating range, only the frequencies that the sub and the mid driver are producing in common, and the wavelengths are relatively similar across those bands. 
  The wavelength of 100hz is 10.2667ft!  Phase shift aside the arrival time would have to be over 5ft different.  Are you trying to tell me that a crossover will cause enough phase shift to equal the subs being on the ground and the mains being on the stage?  Give me a worldly example of a crossover setting that would cause a phase difference of more than a half cycle in any of the frequencies that overlap on a sub and a mid driver.
  I did not claim that it would garentee phase alignment,  I just said that it would sum (which is the same thing as saying that it won't cancel).  If that is not correct please convince me.
Title: Re: Choosing the best sub for me
Post by: Jay Barracato on June 18, 2015, 07:14:35 pm
Guys, guys, you do not have to have phase alignment for the speakers to sum, it just has to be close enough to not cancel.  And I don't see why you would need to look at the entire operating range, only the frequencies that the sub and the mid driver are producing in common, and the wavelengths are relatively similar across those bands. 
  The wavelength of 100hz is 10.2667ft!  Phase shift aside the arrival time would have to be over 5ft different.  Are you trying to tell me that a crossover will cause enough phase shift to equal the subs being on the ground and the mains being on the stage?  Give me a worldly example of a crossover setting that would cause a phase difference of more than a half cycle in any of the frequencies that overlap on a sub and a mid driver.
  I did not claim that it would garentee phase alignment,  I just said that it would sum (which is the same thing as saying that it won't cancel).  If that is not correct please convince me.

It will sum differently throughout the pattern.

What I think is missing from Ivan's nice explanation is that good phase response is key to consistency throughout the listening area.

Once I figured out phase it became clear to me why so many poorly set up three way systems have a great suckout in response or mud an octave above the sub crossover.

Sent from my DROID RAZR HD using Tapatalk
Title: Re: Choosing the best sub for me
Post by: Mac Kerr on June 18, 2015, 08:21:22 pm
Guys, guys, you do not have to have phase alignment for the speakers to sum, it just has to be close enough to not cancel.  And I don't see why you would need to look at the entire operating range, only the frequencies that the sub and the mid driver are producing in common, and the wavelengths are relatively similar across those bands. 
 The wavelength of 100hz is 10.2667ft!  Phase shift aside the arrival time would have to be over 5ft different.  Are you trying to tell me that a crossover will cause enough phase shift to equal the subs being on the ground and the mains being on the stage?  Give me a worldly example of a crossover setting that would cause a phase difference of more than a half cycle in any of the frequencies that overlap on a sub and a mid driver.
  I did not claim that it would garentee phase alignment,  I just said that it would sum (which is the same thing as saying that it won't cancel).  If that is not correct please convince me.

Cancellation happens to some amount through 180║ of phase shift, the 180║ from -90║ to -270║ with the maximum at 180║. Summation happens, to some amount, between -90║ and +90║ with the maximum at 0║. For each crossover pole (6dB of filter slope) you get 90║ of shift. A 12dB filter then will have 180║ of shift, which at 100Hz will be about 5', at 80Hz it will be about 7', at 120Hz it will be about 4.5'. An 18dB/oct filter will be 270║, or to use your example, about 3/4 of a cycle, or about 7.5'. The crossover zone for a 100Hz crossover may reach from 80Hz to 120Hz. At different frequencies the phase shift will be different, but at the acoustic crossover point it will have the greatest effect.

Just remember 6dB/oct equals 90║ shift, 12dB/oct equals 180║ shift, 18dB/oct equals 270║. We are not talking about a phase shift of a few degrees, it is in jumps of90 degrees, which is a quarter of a wavelength for as many rotations as the filter topology requires.

This is true whether it is a passive high level crossover, or an active low level crossover.

Mac
Title: Re: Choosing the best sub for me
Post by: Ivan Beaver on June 18, 2015, 09:31:38 pm
Guys, guys, you do not have to have phase alignment for the speakers to sum, it just has to be close enough to not cancel.  And I don't see why you would need to look at the entire operating range, only the frequencies that the sub and the mid driver are producing in common, and the wavelengths are relatively similar across those bands. 
  The wavelength of 100hz is 10.2667ft!  Phase shift aside the arrival time would have to be over 5ft different.  Are you trying to tell me that a crossover will cause enough phase shift to equal the subs being on the ground and the mains being on the stage?  Give me a worldly example of a crossover setting that would cause a phase difference of more than a half cycle in any of the frequencies that overlap on a sub and a mid driver.
  I did not claim that it would garentee phase alignment,  I just said that it would sum (which is the same thing as saying that it won't cancel).  If that is not correct please convince me.
Have you ever actually LOOKED at the amplitude and phase response?

You can have addition/cancellation a good octave or more above and below crossover freq.

Just "getting it right" at a single freq DOES NOT mean that it will be good above or below the crossover freq.

You can get addition at crossover-and cancellation notches higher and lower in freq.

Hence the reason to ACTUALLY MEASURE the response-NOT just use a single tone at crossover.  You can EASILY be mislead by the "single tone method". 

I will agree that there is some "room to move around" in the delay time.

But it all depends on whether you just want to get it close-or right.

A properly tuned instrument sounds better than one that is "pretty close".
Title: Re: Choosing the best sub for me
Post by: Jacob Shaw on June 19, 2015, 12:52:14 am
I feel we are starting to come to a consensus.  On the point of phase shift due to crossover, if what Mac was saying is accurate, then I stand corrected.  I would like to understand how a crossover effects phase so much.  I think it ought to be a new thread though.  Which forum should it be in?
Title: Re: Choosing the best sub for me
Post by: Scott Holtzman on June 19, 2015, 01:51:41 am
I feel we are starting to come to a consensus.  On the point of phase shift due to crossover, if what Mac was saying is accurate, then I stand corrected.  I would like to understand how a crossover effects phase so much.  I think it ought to be a new thread though.  Which forum should it be in?

Before starting the new thread read up on ELI the ICE man.  Until I heard that mnemonic I struggled remembering phase relationships.

I Googled it to make sure they are still using it pedagogically and indeed the first three hits were awesome explanations.

Good luck on your quest.

BTW-Remember crossover is such a broad term.  It can be as simple as an unpolarized cap in series with a voice coil (inductance and capacitance) to a complex LCR network. 



Title: Re: Choosing the best sub for me
Post by: Jacob Shaw on June 19, 2015, 05:16:40 am
So I went back and did some reading and found that my example would need to be on an LR-4 or LR-8 crossover to work because they do not put the two signals so far out of phase like a 1st order butterworth for example.  The one thing I am not clear on though is dsp such as driverack.  Are LR filters the same magic on dsp or are all dsp crossovers time aligned?  Are there actually series of capacitors and resistors in a driverack or does that stuff work totally different?  Maybe that question will be answered when I do the "ICE man" suggested reading.  Also I am still having trouble wrapping my head around how a HP advances the signal.  Sounds like the circuitry would have to be predictive, which is of course silly.
Title: Re: Choosing the best sub for me
Post by: Ivan Beaver on June 19, 2015, 09:42:36 pm
I feel we are starting to come to a consensus.  On the point of phase shift due to crossover, if what Mac was saying is accurate, then I stand corrected.  I would like to understand how a crossover effects phase so much.  I think it ought to be a new thread though.  Which forum should it be in?
Just use any measurement system and look at the phase response

Run it through a high and low pass filter and observe
Title: Re: Choosing the best sub for me
Post by: Jacob Shaw on June 20, 2015, 03:57:03 pm
Looking at the results of measurement does not seem to explain why the phase shift occurs, only that it occurs.  The concept that I am grappling with is how you can have negative latency.  Eli the ice man did help a little in explaining the phase relationship between current and voltage, although I will have to ponder on how this applies to latency in audio.
Title: Re: Choosing the best sub for me
Post by: Caleb Dueck on June 20, 2015, 04:01:14 pm
You can't have negative latency, IE time travel.  Just added latency, IE delay, on the relatively early arrivals.

Look up how high and low pass filters work, electrically speaking.
Title: Re: Choosing the best phase for me
Post by: Mac Kerr on June 20, 2015, 09:03:05 pm
Looking at the results of measurement does not seem to explain why the phase shift occurs, only that it occurs.  The concept that I am grappling with is how you can have negative latency.  Eli the ice man did help a little in explaining the phase relationship between current and voltage, although I will have to ponder on how this applies to latency in audio.

You don't have negative latency, you have PHASE SHIFT, the 2 are not the same thing. The only thing similar is that we use delay to partially fix phase alignment between 2 speakers that have a phase offset between them. Because we are not correcting the actual phase we can only fix it over a limited range, but that is usually enough to get us good summation through the crossover range. I use the term crossover range because it is in fact a range that is centered around the actual acoustic crossover frequency.

With modern digital processing we can fix the phase, but that would involve negative latency, which is not possible, so we shift everything later so everything is in the positive time domain. This is much of the reason correcting phase with FIR filters induces so much latency.

Mac
Title: Re: Choosing the best phase for me
Post by: Ivan Beaver on June 20, 2015, 10:12:16 pm
Y I use the term crossover range because it is in fact a range that is centered around the actual acoustic crossover frequency.


Mac
And just to add-it is the ACOUSTIC crossover we are interested in, NOT the ELECTRICAL crossover.  Those are often very different-sometimes on the order of an octave.-but easily a half octave.
Title: Re: Choosing the best sub for me
Post by: Jacob Shaw on June 22, 2015, 11:20:00 am
According to what I read in a paper published by rane, a low pass causes a negative shift in phase near the crossover frequency, and a highpass causes a positive shift near the crossover frequency.  This suggests that a transducer receives the signal near the crossover frequency before it receives the higher frequencies.  How is this possible?  I understand how a capasitor can delay a signal because it stores energy, but how can a circuit advance a voltage signal?
Title: Re: Choosing the best sub for me
Post by: Ivan Beaver on June 22, 2015, 01:20:48 pm
According to what I read in a paper published by rane, a low pass causes a negative shift in phase near the crossover frequency, and a highpass causes a positive shift near the crossover frequency.  This suggests that a transducer receives the signal near the crossover frequency before it receives the higher frequencies.  How is this possible?  I understand how a capasitor can delay a signal because it stores energy, but how can a circuit advance a voltage signal?
It is all "relative". One point relative to another.

 If you change your reference point, the phase will change.

Just look at the phase trace on any measurement program.  Now change the delay time and the phase will change.

It is simply the phase as relative to the delay time.
Title: Re: Choosing the best sub for me
Post by: Tim McCulloch on June 23, 2015, 09:36:32 am
I feel we are starting to come to a consensus.  On the point of phase shift due to crossover, if what Mac was saying is accurate, then I stand corrected.  I would like to understand how a crossover effects phase so much.  I think it ought to be a new thread though.  Which forum should it be in?

You need to read up on filters in general, and how they work.  The generic answer is "time."  The lower the center/corner frequency (as appropriate to the type of filter) and the steeper the slope (the number of poles to the filter), the longer it takes for the filter to do its job.

I was ready to give you the Flaming Twit Award (Mac is correct in his statements, and then some) but your interest in furthering your knowledge has postponed the ceremony.  It's reasonable to want to understand most fully the things that influence the DUT, but it's also acceptable to take to heart the statements of Mac, Ivan, Caleb and most of the others that have responded to your assertions.  They really DO know their shit and aren't just jerking your chain.

You would benefit from learning more about *measurement* as time (phase) is as the heart and soul of the process.  It's still up to the operator to make decisions about what is seen in Smaart/SysTune displays, but without these tools you're flying time-blind.

Does phase alignment make a difference?  Hell yes.  I did impulse alignments for a very long time and those represented an improvement over my prior techniques (flipping polarity of a pass band and delaying for max cancellation at crossover, then flipping back).  Jamie Anderson opened my ears and eyes in my first Smaart class in 2004.  I've never gone back to Thee Olde Wayz.  How much of a difference can phase alignment make?  Up to 6dB across almost 2 octaves.  Proper alignment can cut a significant amount of stuff from the truck pack.  The accountant likes that, the crew likes that, and the rigs sound better.
Title: Re: Choosing the best sub for me
Post by: Ivan Beaver on June 23, 2015, 12:42:43 pm

Does phase alignment make a difference?  Hell yes.  I did impulse alignments for a very long time and those represented an improvement over my prior techniques (flipping polarity of a pass band and delaying for max cancellation at crossover, then flipping back).  Jamie Anderson opened my ears and eyes in my first Smaart class in 2004.  I've never gone back to Thee Olde Wayz.  How much of a difference can phase alignment make?  Up to 6dB across almost 2 octaves.  Proper alignment can cut a significant amount of stuff from the truck pack.  The accountant likes that, the crew likes that, and the rigs sound better.
The problem with delaying at one freq is that you can get a gain at THAT freq, but yet have dips on either side of crossover and not know it.

When you phase align (getting the drivers to act more like ONE driver), you get a better summation AND better sound quality.

I ALWAYS look an octave on either side of acoustic crossover to make sure I am not getting cancellations.

As with anything you have to look at the OVERALL issue-not just one little piece
Title: Re: Choosing the best sub for me
Post by: Jacob Shaw on June 23, 2015, 12:47:09 pm
I don't believe anyone is trying to mislead me, but I have read up on how crossover networks work, and I don't see that anyone has taken a stab at directly answering my question. 
  If you have a lonely 10" transducer on a highpass filter,  what causes it to reproduce the frequencies near the corner ahead of the higher frequencies? 
Title: Re: Choosing the best sub for me
Post by: Scott Carneval on June 23, 2015, 01:58:52 pm
I don't believe anyone is trying to mislead me, but I have read up on how crossover networks work, and I don't see that anyone has taken a stab at directly answering my question. 
  If you have a lonely 10" transducer on a highpass filter,  what causes it to reproduce the frequencies near the corner ahead of the higher frequencies?

They aren't reproduced 'ahead in time'.  That's simply not possible.  Phase isn't time and time isn't phase.  Phase varies over time and therefore if you adjust time, you CAN adjust phase.  The frequencies aren't produced ahead in time, but they DO originate at a different degree of phase.  So the goal is to time-align each passband so that the x-over frequencies are in phase. 
Title: Re: Choosing the best sub for me
Post by: Scott Carneval on June 23, 2015, 02:04:00 pm
I don't believe anyone is trying to mislead me, but I have read up on how crossover networks work, and I don't see that anyone has taken a stab at directly answering my question. 
  If you have a lonely 10" transducer on a highpass filter,  what causes it to reproduce the frequencies near the corner ahead of the higher frequencies?

No, one is trying to mislead you, but this is a very complicated subject and not one that is easy to wrap your head around for the first time.  It helps a lot to have a graphical representation of what's going on. I would suggest searching youtube I'm sure someone has put together a good video on it. 

It wasn't until I attended a 3-day SMAART class that I began to understand what was going on. 
Title: Re: Choosing the best sub for me
Post by: Jacob Shaw on June 23, 2015, 03:14:26 pm
"But it does originate at a different degree of phase". That's it!  It clicks now!  Big ups Scott, you nailed it.
Title: Re: Choosing the best sub for me
Post by: Jacob Shaw on June 23, 2015, 03:17:11 pm
So does a LR 4 filter really correct this problem as long as the drivers are spacially aligned?
Title: Re: Choosing the best sub for me
Post by: Scott Carneval on June 23, 2015, 03:34:42 pm

So does a LR 4 filter really correct this problem as long as the drivers are spacially aligned?

Are you suggesting a 4db per octave crossover?  I don't think that's steep enough to be useful. If it really bothers you, you can look into FIR or Finite Impulse Response filters. But they have drawbacks too as they add overall latency to the entire system.

I think you're concerning yourself too much with fixing something that really can't be fixed. Like everything else in audio, it's a compromise. For most situations the best compromise is using a little bit of delay to phase align each passband through the crossover region.


Sent from my iPhone using Tapatalk
Title: Re: Choosing the best sub for me
Post by: Mac Kerr on June 23, 2015, 04:00:38 pm
Are you suggesting a 4db per octave crossover?

No, a LR 4 is a 4 pole is a 24dB/oct Linkwitz Riley filter (https://en.wikipedia.org/wiki/LinkwitzľRiley_filter). It has 360║ of phase rotation.

Mac
Title: Re: Choosing the best sub for me
Post by: Scott Carneval on June 23, 2015, 04:05:13 pm
No, a LR 4 is a 4 pole is a 24dB/oct Linkwitz Riley filter (https://en.wikipedia.org/wiki/LinkwitzľRiley_filter). It has 360║ of phase rotation.

Mac

Gotcha.  I've just always called that a LR-24.
Title: Re: Choosing the best sub for me
Post by: Ivan Beaver on June 23, 2015, 08:42:15 pm
"But it does originate at a different degree of phase". That's it!  It clicks now!  Big ups Scott, you nailed it.
Think of it like this.

Lets say you draw a number of different freq sine waves on a graph.

And you start them all at 0 time and 0 amplitude.

Now choose a point anywhere else along the graph.  The frequencies will have all sorts of phase relationships.

There is almost no possibility that they will all be in phase-unless they are all multiples of each others.

Phase is not so much "absolute" but rather relative to something else.
Title: Re: Choosing the best sub for me
Post by: Jacob Shaw on June 24, 2015, 03:36:07 pm
Yes Scott, the 360 degrees of phase rotation is what I am referring to.  Mr.linkwitz and mr. Riley developed their filter by putting butterworth filters in sequence in an attempt to address the problems of phase shift and amplitude bump simultaneously, and supposedly it works at certain intervals.  So you should be able to spacially align the drivers and use this type of filter and the drivers will sum just fine as long as they are vertically arranged and in close proximity.
Title: Re: Choosing the best sub for me
Post by: Mac Kerr on June 24, 2015, 03:49:06 pm
Yes Scott, the 360 degrees of phase rotation is what I am referring to.  Mr.linkwitz and mr. Riley developed their filter by putting butterworth filters in sequence in an attempt to address the problems of phase shift and amplitude bump simultaneously, and supposedly it works at certain intervals.  So you should be able to spacially align the drivers and use this type of filter and the drivers will sum just fine as long as they are vertically arranged and in close proximity.

The filters will sum correctly at some frequency, but will still be 360║ out of phase. The acoustic summation also depends on the actual response of the speakers, which being different types of speakers will not be the same.

Mac