Question

All channels are assigned to just one of either sub 1,2, 3, or 4 for a play with 20 body mics. The subs are assigned to the main. When the sub faders are off, the channels are some of the time (50%) passing a reduced sound / signal to the main, even when the channel faders are off as well. The only way to stop this happening is to mute all the channels.

Also this is not happening all the time. Sometimes it's operating as expected, and then next thing channels are coming thru at moderate volume with the channel and sub faders off.

This is a major problem. Help, please!

Answer 1

P.S.

Muting the sub groups does not stop the unwanted audio coming out the mains. This suggests to me that the desk is passing audio from the channel to the mains even though it is not told / instructed to do this.

Thanks

Answer 2

I could think of some signals sent through FX A or FX B to Mains, but as they are post fade this is probably not the reason. So your problem looks like a typical fader problem (how old is your board, how often has it been used, has there been some dust/moist/ice...?), which means that the fader banks need to be replaced. You may want to check, which channels "bypass" the faders. If I remember it right one fader bank is 8 channels (1 to 8, 9 to 16, 17 to 24, Groups & Main). But I would recommend to replace ALL faders, because they were a weak part in the classic mixers. The faders could easily get dirty inside, which causes misfunctions (like letting signals go through). Replacing all faders is affordable and gives you some more good years with your board.