This is because mixing consoles typically output line-level audio into the eight input jacks of the S-0816. In order to accommodate these line-level signals, you need to pad the inputs on the S-0816 unit. To pad these inputs, use the S-4000R remote control or optional RCS software to engage the 20dB pad on each S-0816 input. Simply select inputs 17 through 24 and engage each pad. This will restore normal audio on your returns to the stage unit.