ProSoundWeb Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: 1 ... 4 5 [6] 7 8 ... 11   Go Down

Author Topic: Choosing the best sub for me  (Read 19649 times)

Ivan Beaver

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 8778
  • Atlanta GA
Re: Choosing the best sub for me
« Reply #50 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.
Logged
A complex question is easily answered by a simple-easy to understand WRONG answer!

Ivan Beaver
Danley Sound Labs

PHYSICS- NOT FADS!

Ivan Beaver

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 8778
  • Atlanta GA
Re: Choosing the best sub for me
« Reply #51 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????????
Logged
A complex question is easily answered by a simple-easy to understand WRONG answer!

Ivan Beaver
Danley Sound Labs

PHYSICS- NOT FADS!

Ivan Beaver

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 8778
  • Atlanta GA
Re: Choosing the best sub for me
« Reply #52 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.
Logged
A complex question is easily answered by a simple-easy to understand WRONG answer!

Ivan Beaver
Danley Sound Labs

PHYSICS- NOT FADS!

Alex Berry

  • Newbie
  • *
  • Offline Offline
  • Posts: 41
Re: Choosing the best sub for me
« Reply #53 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.
Logged

Alex Berry

  • Newbie
  • *
  • Offline Offline
  • Posts: 41
Re: Choosing the best sub for me
« Reply #54 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.
Logged

Doug Fowler

  • Member since May 1995, 2nd poster on original LAB, moderator on and off since 1997, now running TurboMOD v1.826
  • Administrator
  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1686
  • Saint Louis, MO USA
Re: Choosing the best sub for me
« Reply #55 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.

Logged
"It's got electrolytes.  It's got what plants crave."

Alex Berry

  • Newbie
  • *
  • Offline Offline
  • Posts: 41
Re: Choosing the best sub for me
« Reply #56 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.
Logged

Tim Weaver

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2167
  • College Station, Texas
    • Daniela Weaver Photography
Re: Choosing the best sub for me
« Reply #57 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.
Logged
Bullwinkle: This is the amplifier, which amplifies the sound. This is the Preamplifier which, of course, amplifies the pree's.

Ivan Beaver

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 8778
  • Atlanta GA
Re: Choosing the best sub for me
« Reply #58 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.
Logged
A complex question is easily answered by a simple-easy to understand WRONG answer!

Ivan Beaver
Danley Sound Labs

PHYSICS- NOT FADS!

Doug Fowler

  • Member since May 1995, 2nd poster on original LAB, moderator on and off since 1997, now running TurboMOD v1.826
  • Administrator
  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1686
  • Saint Louis, MO USA
Re: Choosing the best sub for me
« Reply #59 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.
Logged
"It's got electrolytes.  It's got what plants crave."
Pages: 1 ... 4 5 [6] 7 8 ... 11   Go Up
 


Page created in 0.039 seconds with 21 queries.