ProSoundWeb Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: 1 [2] 3 4   Go Down

Author Topic: Bridged amps and stereo playback  (Read 7004 times)

John Roberts {JR}

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 16610
  • Hickory, Mississippi, USA
    • Resotune
Re: Bridged amps and stereo playback
« Reply #10 on: October 14, 2016, 09:56:11 am »

No no no

Do not do this

Due to the loading from the other channel you will get distortion and possibly damage the output of the console

You y to split with no problems but never ever y to combine signals
True, in general you should not Y outputs together. If both are low impedance you are effectively driving one output into the other. If you hear distortion in that Y output it is caused by current limiting as the two outputs fight each other (one is zigging while the other one zags).

That said this is not a new issue and many manufacturers anticipate customers making such ill advised connections, so incorporate build out impedances (series resistors), Shorting two impedance protected outputs will form a simple voltage divider (in other words it works).

So YMMV. Hard output Y connections are not best practice but will probably work in modern well engineered products.

JR

PS: One could make a very inexpensive Y cable with resistors built in, somebody probably does.
Logged
Don't tune your drums half-ass. Listen to what a properly "cleared" drum sounds like.   http://circularscience.com/

Tim McCulloch

  • SR Forums
  • Hero Member
  • *
  • Offline Offline
  • Posts: 21503
  • Wichita, Kansas USA
Re: Bridged amps and stereo playback
« Reply #11 on: October 14, 2016, 09:57:51 am »

Radial makes a direct box that will sum the left + right output from your music device into a single channel. The output from the direct box then goes to your mixer and only uses 1 channel.
The Radial AV-1.  Street price of $100 or so probably puts it out of Jeffrey's budget.

Rapco has a Blox model with 3.5mm trs plug, a level control and XLR-M output.  If Jeffrey has an avalable mic input the Blox unit in much cheaper.  One of the housemen at our downtown Hyatt Regency bought one to play his phone over the ceiling speakers.. >:(
Logged
"Practicing an art, no matter how well or badly, is a way to make your soul grow, for heaven's sake. Sing in the shower. Dance to the radio. Tell stories. Write a poem to a friend, even a lousy poem. Do it as well as you possible can. You will get an enormous reward. You will have created something."  - Kurt Vonnegut

Scott Olewiler

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1193
  • Trust me, it will be loud enough.
    • 4th Street Sound
Re: Bridged amps and stereo playback
« Reply #12 on: October 14, 2016, 10:02:51 am »

What's the reason for bridging your amps?

What do you hope to accomplish?

Correct me if I'm wrong but...

When you bridge an amp, doesn't the the same input produces more output initially, but then you still "max" out at the same level as you would if you were in stereo?  My experiments with subs have shown the same speaker output hitting the limit lights bridged as I got htting them in stereo.
« Last Edit: October 14, 2016, 10:13:15 am by Scott Olewiler »
Logged
We're here to deliver the sound equipment. Who has the check?

Scott Olewiler

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1193
  • Trust me, it will be loud enough.
    • 4th Street Sound
Re: Bridged amps and stereo playback
« Reply #13 on: October 14, 2016, 10:05:05 am »

The Radial AV-1.  Street price of $100 or so probably puts it out of Jeffrey's budget.

Rapco has a Blox model with 3.5mm trs plug, a level control and XLR-M output.  If Jeffrey has an avalable mic input the Blox unit in much cheaper.  One of the housemen at our downtown Hyatt Regency bought one to play his phone over the ceiling speakers.. >:(

With two RCA to 1/4 adapters the Radial StageBug SB-2 will do it for $70.
« Last Edit: October 14, 2016, 10:10:59 am by Scott Olewiler »
Logged
We're here to deliver the sound equipment. Who has the check?

Jamin Lynch

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1949
  • Corpus Christi, TX.
Re: Bridged amps and stereo playback
« Reply #14 on: October 14, 2016, 11:09:38 am »

Correct me if I'm wrong but...

When you bridge an amp, doesn't the the same input produces more output initially, but then you still "max" out at the same level as you would if you were in stereo?  My experiments with subs have shown the same speaker output hitting the limit lights bridged as I got htting them in stereo.

That's kind of what I was eluding to. Is there really a good reason to bridge in the first place?

It would be nice to know what speakers and amps the OP is using.
Logged
"At first you don't succeed, go back to the drawing board."

Don Boomer

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 298
    • RF Venue
Re: Bridged amps and stereo playback
« Reply #15 on: October 14, 2016, 11:28:41 am »


Also, what about the RCA stereo channels at the end of my board I use for playback music between sets? I have (2) set of RCA channels like that. Can I put Red RCA in red left then pan left, Then put White RCA in next channel red left , then pan left? Would that get my stereo playback at least back to where I can hear the FULL song? You know 1/2 of it missing?

Interesting question. You may not get the FULL song when combining the two sides as there could be a fair amount of cancellation from phase shift. It will depend on the material. For me anyway, if this is just background break music I'd just play one side and be done with it.
Logged
Don Boomer
Senior applications engineer
RF Venue, Inc.

Mark Wilkinson

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1011
Re: Bridged amps and stereo playback
« Reply #16 on: October 14, 2016, 12:24:51 pm »

Correct me if I'm wrong but...

When you bridge an amp, doesn't the the same input produces more output initially, but then you still "max" out at the same level as you would if you were in stereo?  My experiments with subs have shown the same speaker output hitting the limit lights bridged as I got htting them in stereo.

IME, and going by most all amp specs I've read...there are only two cases I know of where bridging makes sense.... where real power is gained.

.....a single 8 or 4 ohm box will obviously get alot more power bridged than on a single channel.
.... for a couple of 8 ohm boxes wired parallel, bridged produces real power gains vs having each sub on its own single channel.

If you have 4 ohm subs, nothing is to be gained by bridging.  In-series is usually a power wash by the specs , and in-parallel is almost always a 2 ohm no-no

Logged

Jay Marr

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 661
Re: Bridged amps and stereo playback
« Reply #17 on: October 14, 2016, 12:48:01 pm »

.
.... for a couple of 8 ohm boxes wired parallel, bridged produces real power gains vs having each sub on its own single channel.


I would guess this is the case for the OP.
If he has 2 boxes for tops and subs, they're likely 8ohm boxes and he's getting more power bridging an amp to get max 4ohm output.
Logged

Art Welter

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1727
Re: Bridged amps and stereo playback
« Reply #18 on: October 14, 2016, 12:59:26 pm »

That's kind of what I was eluding to. Is there really a good reason to bridge in the first place?
Perhaps what is eluding you is in many cases the amp will deliver it's full two channel output to the single load.

As an example of a good reason to use the  bridge mono option, I use one four channel NU4-6000 per side to drive my mains, a bridged pair for the 2x8 ohm lows, one channel for mids, one channel for highs.

If I were to use one channel for each 8 ohm low speaker, each would get only 440 watts peak. The same two channels bridged mono driving a four ohm pair deliver 3000 watts peak, almost 6 dB more "whoopee", a Really Big Deal at 40 Hz, where a 6 dB increase in SPL sounds twice as loud.

Good enough reason for me, and the NU4-6000 run cool with all channels driven to full tilt boogie in the hot summer sun, now turning into the hot fall sun here in sunny (when hurricanes are not wrecking things) Florida.

Art

« Last Edit: October 14, 2016, 01:01:38 pm by Art Welter »
Logged

John Roberts {JR}

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 16610
  • Hickory, Mississippi, USA
    • Resotune
Re: Bridged amps and stereo playback
« Reply #19 on: October 14, 2016, 01:07:48 pm »

IME, and going by most all amp specs I've read...there are only two cases I know of where bridging makes sense.... where real power is gained.

.....a single 8 or 4 ohm box will obviously get alot more power bridged than on a single channel.
.... for a couple of 8 ohm boxes wired parallel, bridged produces real power gains vs having each sub on its own single channel.

If you have 4 ohm subs, nothing is to be gained by bridging.  In-series is usually a power wash by the specs , and in-parallel is almost always a 2 ohm no-no
This is an extremely old topic.. maybe perform a search.

JR
Logged
Don't tune your drums half-ass. Listen to what a properly "cleared" drum sounds like.   http://circularscience.com/

ProSoundWeb Community

Re: Bridged amps and stereo playback
« Reply #19 on: October 14, 2016, 01:07:48 pm »


Pages: 1 [2] 3 4   Go Up
 



Page created in 0.125 seconds with 24 queries.