Optimum Volume knob, audio out and mixer settings for pa4x

[olegnakorg]

I have my pa4x connected to a little mixer which then is connected to a mixer main. I use 4 outputs from the pa4x to the little personal mixer, Left, Right And outs 1 and 2 for separate bass and drums control. What is the optimum level for the volume knob on the keyboard, the audio out settings in global and the volume settings on the little local mixer before sending to main mixer. If the volumes are too low the sound is not very good. If the volumes are too high then there is peaking and distortion in the main mixer. Thank you for your help in advance