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William Hepburn
03-28-2010, 03:37 PM
This is my first post so....Hi

I was an audiophile 20 years ago, before 5 kids. I got a bit distracted. However, I'm on the board of a local community theater and one of the few who know anything about audio, not that I'm an expert.

The building we are using for our theater is built like an old movie theater, shotgun style. During kids productions especially, it's almost impossible to make out the dialog in the rear rows 60' back.

We have some hanging mics over the stage running through a decent board. We have a couple of PA speakers near the 20' ceiling in the front above the stage, driven by an old Ross Systems Amp. I bought an Adcom GFA 2535 to run four satellite speakers (just cheapies) I've mounted on the walls 1/2 and 3/4 of the way back from the stage in hopes of merely reinforcing the dialog.

I see no point in running sterio since it's practically inpossible to operate the faders properly to keep left and right seperate. The Adcom has amp A & B with both L&R each. How would one wire these? Will brigded mono (from a single input) generate identical signals on all four channels?

I'm open to suggestions.


03-28-2010, 05:17 PM
Amplifier B can be bridged to run mono. So whatever goes in the left channel of B would go out through the bridged connection to one speaker. Amplifier A would still be stereo. This isn't producing four identical signals from one source. The GFA-2535 passes through up to four signals to as many as four speakers. Amp B can be combined to run only one speaker.

03-28-2010, 05:30 PM
I guess I could also address the question of how to wire them. When you're in mono mode, you use the Left Red and the Right Red to a single speaker.

William Hepburn
03-29-2010, 05:43 AM
Thanks for the info. Acutally I found a manual on line that confirms what you've said.

I guess another questions would be what to do about mono vs stereo in this application. I'll likely be using a Samick SM 82, 8 channel board that touts it's L & R capabilities. This will be a sub board patched into our main sound board which also has Stereo out. Should I try to maintain Stereo sound or just go mono? And depending upon the answer to that question, how about speaker placement?

Again the "house" is about 25' wide and 70' - 80' long and not an acoustic masterpiece

03-29-2010, 06:12 AM
Near the back of the the problem volume or is it clarity?

03-29-2010, 07:08 PM
I suppose you might have already gotten your answers somewhere else, but I think the answer to the stereo question is probably that it's best to go all mono with a high (close to the ceiling) point source in the front of the room and acoustical wall treatment.