Hi,
Just change your output configuration. I guess that your configuration is:
Main (L-R) bus to FOH
Matrix1 bus to USB recorder.
Change it to:
Main (L-R) bus to USB recorder ; and put it to unity (= 0 dB)
Matrix1 bus to FOH. This is your main volume control now.
Don’t forget to set L-R mix to unity in the matrix1 bus and you have to reconfigure your Main L-R outputs to Matrix1 L-R out on your stage frame.
This give you also the advantage that you don’t use the Main L-R PEQ/GEQ. So the recording on USB is without EQ adjustments for the room / PA system. Do your room/PA eq adjustments in the Matrix bus. (Same for other things like compressor ; delay ; …)
good luck.
regards.
Pascal
GLD80