My wife plays keys in our duo. She plays the keyboard split with bass on the bottom and other sounds on the top. I wanted the audio to split to two different channels on the board using the keyboard volume for the bass and an inline volume pedal for the upper keyboard. I was hoping the right and left audio outs would be discreet, and not have signal from the other section of the keyboard. She has a hard time with working the volume as the bass signal is still present in the other channel. I thought I had programmed the zones totally independent, but maybe I'm missing something. Any thoughts?