ProSoundWeb Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: [1] 2 3 ... 5   Go Down

Author Topic: Having a problem with subs....  (Read 17388 times)

Demetrius Garland

  • Newbie
  • *
  • Offline Offline
  • Posts: 13
Having a problem with subs....
« on: July 07, 2012, 05:42:07 pm »

Hello Board....Ive been trying to help my friend with his subs that he has installed in his church. The problem is they are not putting out half of what they should be, and as soon as you start to hear them a little the amp clip light comes on. Weve tried getting a powered sub and connected to the same output wire from the board (bypassing amps of course) and still not getting at least decent bottom. For our mixing board he is using a Behringer SX2442FX, The subs are Carvin TR1801, and a 2000watt crown amp. He is using the mono out on the board to send signal, the line has a female to female adapter in it to extend it. Its going to a  31Band EQ than to the amp. The amp is in bridge mode. To add to it when we unplug the subs from the amp it still clips. Hes almost maxing out the mono fader just to get a little sound from the subs. This is even with playing an audio CD. The signal at the input is good. Input level on channels are about -5db. Weve been trying to diganose this for a while. Any help would be greatly appreciated!!!! Thanks
Logged

Lee Buckalew

  • Classic LAB
  • Hero Member
  • *
  • Offline Offline
  • Posts: 1346
  • St. Louis, MO area
    • Pro Sound Advice, Inc.
Re: Having a problem with subs....
« Reply #1 on: July 07, 2012, 06:12:05 pm »

Hello Board....Ive been trying to help my friend with his subs that he has installed in his church. The problem is they are not putting out half of what they should be,

How do you know, have you measured it or is this like tuning a car and then going by the seat of your pants to judge if you improved the performance?


as soon as you start to hear them a little the amp clip light comes on

The clip light coming on means that the amp is clipping.  It may be outputting it's full power, it may not.  You'd have to measure the output to know.  These speakers won't output much as far as subs go.  The continuous capability, before power compression, is about 124dB/SPL at 1 meter for a single sub cabinet.  You have not said what amp model this is.  Two subs connected in parallel may or may not be O.K. for the amp that's being used.  If the amp is actually capable of 2000 watts at 8 ohms per channel, I would not bridge it, I'd run it parallel mono given the mono console feed.

Another potential issue here could be speaker mounting.  If they have tried to build these into the structure somehow, most likely they have created problems.  It takes a lot of very tight fitting and very dense construction to build in subs so that they work well.


Lee
Logged
Lee Buckalew
Pro Sound Advice, Inc.

Brad Weber

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2209
  • Marietta, GA
Re: Having a problem with subs....
« Reply #2 on: July 07, 2012, 06:56:58 pm »

For our mixing board he is using a Behringer SX2442FX, The subs are Carvin TR1801, and a 2000watt crown amp. He is using the mono out on the board to send signal, the line has a female to female adapter in it to extend it.
On the mono output, at the Mono fader is the low pass filter activated and what frequency is set for the filter?
 
The Mono output on that mixer is an unbalanced 1/4" TS connector, so I'm rather confused on how it is wired.  But it being unbalanced with a maximum output 6dB below the balanced main outputs may explain part of of the lower level.  And if that is not wired properly to the following device it may explain an even greater difference.
 
Its going to a  31Band EQ than to the amp.
What are you doing with the EQ?  Any chance you may be filtering out all of the low end?  And are you doing anything to filter the low frequencies out of the mains?
 
The amp is in bridge mode.
Are the inputs and outputs properly wired for bridge mode operation?
Logged

John Halliburton

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 802
  • White pointy beard, knows zip...about chicken.
Re: Having a problem with subs....
« Reply #3 on: July 07, 2012, 06:58:52 pm »

Hello Board....Ive been trying to help my friend with his subs that he has installed in his church. The problem is they are not putting out half of what they should be, and as soon as you start to hear them a little the amp clip light comes on. Weve tried getting a powered sub and connected to the same output wire from the board (bypassing amps of course) and still not getting at least decent bottom. For our mixing board he is using a Behringer SX2442FX, The subs are Carvin TR1801, and a 2000watt crown amp. He is using the mono out on the board to send signal, the line has a female to female adapter in it to extend it. Its going to a  31Band EQ than to the amp. The amp is in bridge mode. To add to it when we unplug the subs from the amp it still clips. Hes almost maxing out the mono fader just to get a little sound from the subs. This is even with playing an audio CD. The signal at the input is good. Input level on channels are about -5db. Weve been trying to diganose this for a while. Any help would be greatly appreciated!!!! Thanks

A couple of things:

First, are you using an electronic crossover in the feed from the mono out jack on the mixer?  Using just an equalizer won't really let you set the system up properly.  At this point I'd be suspect of  how you have the equalizer set-it could be killing the gain structure.

Second, there's a possibility that the two subs are somehow being wired up with reversed polarity between them, which would kill most of the low frequency output.

Also, make sure the on board equalizer doesn't affect the mono output-if it does, and you're cutting the low frequency faders, it would kill the subwoofer output.

Best regards,

John
Logged

James A. Griffin

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 832
Re: Having a problem with subs....
« Reply #4 on: July 07, 2012, 07:39:30 pm »

What is placement of subs in room?   Both flown in center?   Both on ground, 1 per corner?
Logged
I need to determine where in this swamp of unbalanced formulas squatteth the Toad of Truth

Ivan Beaver

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 9090
  • Atlanta GA
Re: Having a problem with subs....
« Reply #5 on: July 08, 2012, 09:00:16 am »

Hello Board....Ive been trying to help my friend with his subs that he has installed in his church. The problem is they are not putting out half of what they should be, and as soon as you start to hear them a little the amp clip light comes on. Weve tried getting a powered sub and connected to the same output wire from the board (bypassing amps of course) and still not getting at least decent bottom. For our mixing board he is using a Behringer SX2442FX, The subs are Carvin TR1801, and a 2000watt crown amp. He is using the mono out on the board to send signal, the line has a female to female adapter in it to extend it. Its going to a  31Band EQ than to the amp. The amp is in bridge mode. To add to it when we unplug the subs from the amp it still clips. Hes almost maxing out the mono fader just to get a little sound from the subs. This is even with playing an audio CD. The signal at the input is good. Input level on channels are about -5db. Weve been trying to diganose this for a while. Any help would be greatly appreciated!!!! Thanks
If the amp is clipping, then 1 of several things is happening.

1: You are simply "out of gas" and that is as loud as it is going to get-maybe you are expecting more out of the system than it can do.

2:  You have a short in the speaker line somewhere-causing the amp to see a lower impedance and it is clipping.  Disconnect the speakers and take several resistance checks- acrosso the actual speaker wires (you should see the DC resistance of the cabinet).  Measure each speaker wire to AC ground-they should both read open.

3: The amp is defective-try another amp
Logged
A complex question is easily answered by a simple-easy to understand WRONG answer!

Ivan Beaver
Danley Sound Labs

PHYSICS- NOT FADS!

Vinny DAgostino

  • Full Member
  • ***
  • Offline Offline
  • Posts: 136
  • Warwick, RI
Re: Having a problem with subs....
« Reply #6 on: July 08, 2012, 10:29:06 am »

Are the inputs and outputs properly wired for bridge mode operation?

My money is on this being the issue.
They may have switched the amplifier into bridge mode, but I am guessing they are not using the two red binding posts for the output.
Logged

duane massey

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1613
Re: Having a problem with subs....
« Reply #7 on: July 08, 2012, 08:31:38 pm »

More info needed. What model amp? How old?
Logged
Duane Massey
Technician, musician, stubborn old guy
Houston, Texas

Charlie Zureki

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1244
  • South Eastern Michigan (near Windsor)
Re: Having a problem with subs....
« Reply #8 on: July 08, 2012, 08:49:02 pm »

More info needed. What model amp? How old?

   Hello,


  I guessing that the poster is got a whole lot of issues that can be addressed.

 1.)  that unbalanced line out for the sub as Brad posted.  straighten this out..
 2.)  that the gain settings from input to output needed to be addressed. On each channel and buss.
 3.)  that the poster may have not been sending a proper signal of strength to the mono output for the channels that matter ....ie:  Kick, Bass, Keys, etc...
 4.)  That the EQ is sucking the signal's output...... remove it if it is on the Sub output.
 5.) that there is nowhere near enough rig for the gig.   Get bigger and better subs and power them appropriately.  One of that model of sub is adequate for my theatre room....maybe....
 6.)  use the net to read the manual of the make and model of amplifier feeding the subwoofer.  It is very possible that any dip switches are in the wrong position AND, that you have the amp's output wired incorrectly.

  Cheers,
  Hammer
 
 
Logged
Do it the right way....don't be a Dino!

Demetrius Garland

  • Newbie
  • *
  • Offline Offline
  • Posts: 13
Re: Having a problem with subs....
« Reply #9 on: July 09, 2012, 08:23:40 am »

Hey...sorry so late, the amp is a Behringer EUROPOWER EP2000. The low pass filter on the mono out is activated and the filter is set at 120hertz. As our mains we have 3000 watts driving 6 15s. The church is about 4000sq feet more wider than longer and the subs are positioned standing up in the far outside corners facing straight. I dont have a SPL meter to check levels but from reading LED meters everything is pretty much at unity gain. Speakers are properly plugged in the two red terminals for bridging. The Eq bands are all down except from 120khz-20khz are set in a frown shape. Thanks for all your help. Let me know if im forgetting any more info. Thanks.
Logged

ProSoundWeb Community

Re: Having a problem with subs....
« Reply #9 on: July 09, 2012, 08:23:40 am »


Pages: [1] 2 3 ... 5   Go Up
 



Page created in 0.055 seconds with 23 queries.