ProSoundWeb Community

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: Onlin Barna on April 13, 2013, 08:48:04 PM

Title: Do horn subwoofers really sound bad indoors?
Post by: Onlin Barna on April 13, 2013, 08:48:04 PM
Hello all,

Im looking at 2x single 21" subwoofers ( 600w RMS, 104dB @ 1m) and Im wondering if they are sound bad indoors? Big horns, they are similar to martin WSX.

Another question about amp. Does anybody have bad experience with behringer nu6000? Somebody said, it might be poor at low frequencies. Is it worth to buy with built in DSP? I would have it only for subs and with active crossover before amps (of course).

Thank you for your answers!
Title: Re: Do horn subwoofers really sound bad indoors?
Post by: Ivan Beaver on April 13, 2013, 09:23:07 PM
Hello all,

Im looking at 2x single 21" subwoofers ( 600w RMS, 104dB @ 1m) and Im wondering if they are sound bad indoors? Big horns, they are similar to martin WSX.

Another question about amp. Does anybody have bad experience with behringer nu6000? Somebody said, it might be poor at low frequencies. Is it worth to buy with built in DSP? I would have it only for subs and with active crossover before amps (of course).

Thank you for your answers!
I don't know of any reason that horns would be any different than regular bass cabinets-I assume you heard that somewhere?

And what would you consider "sounding bad"?  Distortion? freq response? coverage? something else?
Title: Re: Do horn subwoofers really sound bad indoors?
Post by: Onlin Barna on April 13, 2013, 11:53:55 PM
I don't remember who said but it was about sound pressure level, so  volume. "Watts are there, decibels aren't". I couldn't imagine why it could be true, but as you are an expert, now I don't think it is. About amp question, anybody has idea?

edit: as you wrote, its was about coverage.
Title: Re: Do horn subwoofers really sound bad indoors?
Post by: Travis_Valois on April 14, 2013, 12:06:03 AM
Hello all,

Im looking at 2x single 21" subwoofers ( 600w RMS, 104dB @ 1m) and Im wondering if they are sound bad indoors? Big horns, they are similar to martin WSX.

Another question about amp. Does anybody have bad experience with behringer nu6000? Somebody said, it might be poor at low frequencies. Is it worth to buy with built in DSP? I would have it only for subs and with active crossover before amps (of course).

Thank you for your answers!

I hope they don't sound bad, in the club i house tech at, we're running 6xMartin 115 bins (3 per side on a QSC EX4000) and they're more than enough for the room so that we have never commissioned the last 2 bins stored in the back.
Title: Re: Do horn subwoofers really sound bad indoors?
Post by: Ivan Beaver on April 14, 2013, 09:38:05 AM
I don't remember who said but it was about sound pressure level, so  volume. "Watts are there, decibels aren't". I couldn't imagine why it could be true, but as you are an expert, now I don't think it is. About amp question, anybody has idea?

edit: as you wrote, its was about coverage.
Very often people will blame the speakers-when the real problem is how they are being used-deployed-aligned etc.

Let's say a particular setup with front loaded subs works fine in a particular situation.  Then the only thing that changes is horn loaded subs are placed where the front loaded ones were.

Of course things are going to change-the path length arrivals to the listener is going to be different-causing notching/holes in the response and so forth.  If that "hole" happens to be where the kick is tuned-then you have a problem.

But if the system was properly aligned-the "hole" would not be there.--But lets blame the type of sub anyway.

It is much easier to blame the tool than the user------------------------

Title: Re: Do horn subwoofers really sound bad indoors?
Post by: g'bye, Dick Rees on April 14, 2013, 09:58:17 AM
It is much easier to blame the tool than the user------------------------

Unless the user is also a tool........
Title: Re: Do horn subwoofers really sound bad indoors?
Post by: drew gandy on April 14, 2013, 01:09:34 PM
There is often a difference that has to do with the nature of the difference in the radiating surface area and distance from the source.  In a standard vented box the very lowest frequencies are almost entirely radiating from the port.  This is very small in comparison to the mouth area of a typical horn sub. Over the rest of the sub band there is less of a difference in radiating size but still a significant enough difference between the 2 designs to cause some effect. (of course it depends on how big the boxes, how many, how many drivers etc that you are comparing).  Because of this difference in area there will be a difference in the way that the sound rolls off with distance between the 2 types of subs, particularly up close.  The effect can be one where the horn subs don't seem to "hit as hard" up close even though the volume level at the back of the room is roughly the same.  And of course there is also the timing issue that Ivan mentioned that affects not only the alignment with the rest of the system but also the alignment with sound coming from the stage.  Furthermore, remember that at the very bottom of it's operating band, vented boxes as well have quite a bit of "delay".   
Title: Do horn subwoofers really sound bad indoors?
Post by: Samuel Rees on April 14, 2013, 02:26:50 PM
There will be a distance in the way the two sub designs roll off with distance, or a different "throw"? Wasn't the conclusion from a thread a while back, that "throw" doesn't exist? Or am I misunderstanding what is being said here?
Title: Re: Do horn subwoofers really sound bad indoors?
Post by: Ivan Beaver on April 14, 2013, 02:50:06 PM
There will be a distance in the way the two sub designs roll off with distance, or a different "throw"? Wasn't the conclusion from a thread a while back, that "throw" doesn't exist? Or am I misunderstanding what is being said here?
The reason the level doesn't change the same (especially up close) is that with a direct radiator the sound starts to expand right outside the cabinet.

With a horn-the expansion has already begun deep inside the cabinet.  So the point of inverse square loses are not starting at the same point (front of cabinet).

So lets say that with a direct radiator you are 1 M away and getting 100dB.  At 2M it will be 94dB.

With a horn sub if it is 100dB at 1 M-and if we assume a 2M horn length), then at 2M from the front of the cabinet-you are actually 4M from the radiator.  So the difference is not 6dB (from doubling of distance) but rather 2.5dB-IF the sound were expanding in all directions-which it is not.  So the losses would be as much.

So yet another "audio thing" that gets more complicated the deeper you look.
Title: Re: Do horn subwoofers really sound bad indoors?
Post by: Ivan Beaver on April 14, 2013, 02:52:24 PM
The reason the level doesn't change the same (especially up close) is that with a direct radiator the sound starts to expand right outside the cabinet.

With a horn-the expansion has already begun deep inside the cabinet.  So the point of inverse square loses are not starting at the same point (front of cabinet).

So lets say that with a direct radiator you are 1 M away and getting 100dB.  At 2M it will be 94dB.

With a horn sub if it is 100dB at 1 M-and if we assume a 2M horn length), then at 2M from the front of the cabinet-you are actually 4M from the radiator.  So the difference is not 6dB (from doubling of distance) but rather 2.5dB-IF the sound were expanding in all directions-which it is not.  So the losses would be as much.

So yet another "audio thing" that gets more complicated the deeper you look.
And hence the  reason to measure all loudspeakers at a distance-as to to minimize these "short distance" differences.  And then "back calculate" to a 1M "standard".  Even if the cabinet will not be as loud at 1M as the measurement suggests-at least the math works when calculating how the loudspeaker will perform over distances.
Title: Re: Do horn subwoofers really sound bad indoors?
Post by: drew gandy on April 14, 2013, 02:56:57 PM
There will be a distance in the way the two sub designs roll off with distance, or a different "throw"? Wasn't the conclusion from a thread a while back, that "throw" doesn't exist? Or am I misunderstanding what is being said here?

This is a near field type of effect.  You know how Ivan talks about measuring a speaker at 10m and then back calculating a 1m sensitivity?  When the distance that you are from the SRO (sound radiating object) is within a couple multiples of the dimensions of the SRO then you are going to see some "warping" that you won't see at a distance.  Actually, do a google of "Dave Gunness speaker throw".  Likely the second entry will be for a thread in the archive where Dave is quoted about this topic.  He might explain this with greater clarity. 
Title: Do horn subwoofers really sound bad indoors?
Post by: Samuel Rees on April 14, 2013, 03:46:33 PM
Thanks guys, (warning: warm and fuzzies ahead) I learn so much here, I can't thank you pros enough for participating knowing you'll mostly be helping and answering questions. Carry on....
Title: Re: Do horn subwoofers really sound bad indoors?
Post by: sam saponaro on June 01, 2013, 01:41:23 AM
Back befor I had much more knowledge than to "make it work" a band I was(am still)in had a set of JBL 4530 double 15" scoops powered off a Mackie amp and they allways sounded good inside and outside especially comsidering the "mix and match" gear that was strung befor them.
Title: Re: Do horn subwoofers really sound bad indoors?
Post by: Tim McCulloch on June 01, 2013, 04:05:12 PM
Back befor I had much more knowledge than to "make it work" a band I was(am still)in had a set of JBL 4530 double 15" scoops powered off a Mackie amp and they allways sounded good inside and outside especially comsidering the "mix and match" gear that was strung befor them.

Back in the day... in the past century by a couple of decades... we had some very decent gear.  What we didn't have was as many resources for learning, experience, education or training.  Much of what we learned came from articles in trade publications (John Roberts was one of the writers, so were Ken Pohlmann, John Woram...) and buying the books those folks mentioned.  The trial and error approach we had to take in experimenting with what we learned as for most of us there weren't others nearby who could validate or criticize our efforts.  Translate that to "we blew up a lot of stuff back then."   ::)

But to your point... considering what we know now compared to what we knew back then, it's a miracle we could even make sound with soup cans and string.  ;D

I've got part of my old Community-based rig stored in my mom's shed.  I'm thinking that later this fall I'll bug-bomb the shed and drag the tops and mids back here to see what I can get out of them with a measurement session and DSP.

And if I'd known that my BiAmp 2442 would be collectable in 2013, I'd have kept it...
Title: Re: Do horn subwoofers really sound bad indoors?
Post by: Tim Perry on June 01, 2013, 05:05:50 PM
Back in the day... in the past century by a couple of decades... we had some very decent gear.  What we didn't have was as many resources for learning, experience, education or training. 

This should be nominated for the quote of the month.
Title: Re: Do horn subwoofers really sound bad indoors?
Post by: Ivan Beaver on June 01, 2013, 07:39:05 PM
Back in the day... in the past century by a couple of decades... we had some very decent gear.  What we didn't have was as many resources for learning, experience, education or training.  Much of what we learned came from articles in trade publications (John Roberts was one of the writers, so were Ken Pohlmann, John Woram...) and buying the books those folks mentioned.  The trial and error approach we had to take in experimenting with what we learned as for most of us there weren't others nearby who could validate or criticize our efforts.  Translate that to "we blew up a lot of stuff back then."   ::)

But to your point... considering what we know now compared to what we knew back then, it's a miracle we could even make sound with soup cans and string.  ;D

I've got part of my old Community-based rig stored in my mom's shed.  I'm thinking that later this fall I'll bug-bomb the shed and drag the tops and mids back here to see what I can get out of them with a measurement session and DSP.

And if I'd known that my BiAmp 2442 would be collectable in 2013, I'd have kept it...
EXACTLY!!!!!!!!!!!!

BTW I had a Biamp 2442-that I modded (like all my consoles) to give an extra aux send-upgraded the faders and so forth.

However the truly sad thing-is that with SO MUCH freely available information these days-I honestly think the "overall" quality of sound system (all averaged together) is lower than back in those days.

It is sooo easy for anybody to go to GC and buy a system-yet have NO idea how to run or hook it up... And the end result if bad sound.

We have SOOOO many better tools and equipment available to us these days-but that alone does not mean it is going to sound good. :(

The sound only gets better IF the tools are used properly.

Title: Re: Do horn subwoofers really sound bad indoors?
Post by: duane massey on June 02, 2013, 02:24:55 PM
I'm showing my age here (birthday this week) but it sure seems like the quality of engineers goes down when the quality of technology goes up. Making the gear easier dosen't make the operator better.
Can't begin to calculate how many times in the 70's we'd sit down and try to figure out how to design a particular cabinet or electronic gadget, only to eventually say "Screw it" and just build the damn thing. Sometimes it worked, sometimes it failed spectacularly....
Title: Re: Do horn subwoofers really sound bad indoors?
Post by: sam saponaro on June 02, 2013, 06:26:42 PM
I've got part of my old Community-based rig stored in my mom's shed.  I'm thinking that later this fall I'll bug-bomb the shed
Funny you should say that.....my JBL 4530s are in my Mom's shed too.....good thing for moms. Now I almost feel bad she can't fit her lawn mower in the shed with the refridgerator boxes in there..........but whats a PA guy to do....ya know. ;)
Now to dig the A7s outta dad's shed LOL ;D
Title: Re: Do horn subwoofers really sound bad indoors?
Post by: duane massey on June 03, 2013, 01:44:15 AM
I still have a pair of full-sized M4 flares and drivers in my warehouse. Don't have a use for them, but don't want to discard them either. Fixing to move to a different building, and I'm sure they'll  make the trip.
Title: Re: Do horn subwoofers really sound bad indoors?
Post by: Onlin Barna on June 12, 2013, 04:01:17 PM
I have problems both in and outdoor.

I found a suggestion about installing horn subwoofers, here is it: http://www.soundlightcrew.hu/hangfaltervek/rutsevaria.jpg

Not so complicated, I have 2 so I installed as the first pictures shows.

My problem: There is almost nothing bass "kick" in the middle section, I have painted a very poor about how I hear it.

I also tried the subs installing vertically, it's the same.

Here is my masterpiece: http://img811.imageshack.us/img811/1913/subgo.jpg

Red is where I hear nothing bass, at green it kicks very hard.

By the way the subs are 21", 600w but I think that doesn't really matter. The inside of the box is not so complicated, its something similar to what I painted.

Does anybody have idea how should I make it?
Title: Re: Do horn subwoofers really sound bad indoors?
Post by: Tim Weaver on June 12, 2013, 04:26:07 PM
CHeck your polarity. Make sure both cones are pushing out together, then pulling in together. If they are opposite, they will fight each other and give you the response you described.
Title: Re: Do horn subwoofers really sound bad indoors?
Post by: Mac Kerr on June 12, 2013, 05:09:55 PM
I have problems both in and outdoor.

I found a suggestion about installing horn subwoofers, here is it: http://www.soundlightcrew.hu/hangfaltervek/rutsevaria.jpg

Not so complicated, I have 2 so I installed as the first pictures shows.

My problem: There is almost nothing bass "kick" in the middle section, I have painted a very poor about how I hear it.

I also tried the subs installing vertically, it's the same.

Here is my masterpiece: http://img811.imageshack.us/img811/1913/subgo.jpg

Red is where I hear nothing bass, at green it kicks very hard.

By the way the subs are 21", 600w but I think that doesn't really matter. The inside of the box is not so complicated, its something similar to what I painted.

Does anybody have idea how should I make it?

Try unplugging one of the subs to see if it gets better. Your drawing suggests that the subs are out of polarity with each other.

Mac
Title: Re: Do horn subwoofers really sound bad indoors?
Post by: Mike Reigh on June 13, 2013, 10:35:46 AM
I know they're different, but the Martin WSX sub puts the mouths of the subs together (their driver is not exposed like yours).  Have you tried placing the subs as such?  Also agree with driver polarity.
Title: Re: Do horn subwoofers really sound bad indoors?
Post by: Onlin Barna on June 14, 2013, 01:39:26 PM
Thanks for your help very much (I don't know how I didn't find out polarity...)

It's interesting (for me) that now the polarity of the subs are different, and now the sound is very good in the middle. Is it normal? I mean, the polarity is normal at one sub, and changed at the other.

Thanks
Title: Re: Do horn subwoofers really sound bad indoors?
Post by: Mac Kerr on June 14, 2013, 02:01:30 PM
Thanks for your help very much (I don't know how I didn't find out polarity...)

It's interesting (for me) that now the polarity of the subs are different, and now the sound is very good in the middle. Is it normal? I mean, the polarity is normal at one sub, and changed at the other.

Thanks

It is unclear what you mean by that statement. If the output of each sub is in polarity with regards to the other one, they will sum together and be louder than a single sub. If the output of each sub is out of polarity with regards to the other one, they will still sum together, but be less bass than a single sub.

You need to check your wiring from mixer output to subwoofer input to determine that it is all wired correctly to maintain the same polarity throughout the signal chain. If you have had to change the polarity to make the subs add together positively rather than negatively there is something wired wrong.

Mac