The sound does not change even when the crossfader is moved.

Is the CROSS FADER ASSIGN (A, THRU, B) selector switch properly set? Set the [CROSS FADER ASSIGN (A, THRU, B)] selector switches for the respective channels properly. If the INPUT selector switches of CH3/4 are set to MICI1/MIC2, the sound does not change even when the crossfader is moved, regardless of the position of the CROSS FADER ASSIGN selector switches.