If he's using the EQ on the mixer than I suggest he set the 740's EQ to FLAT. Otherwise he's going to run into some crazy output there If he uses the EQ on the 740 he needs to flatline the EQ on the mixer. Also he may be able to find a middle ground by adjusting the EQ on the 740 and the Mixer so that they compliment eachother and not overpower one or the other.

GEAR: Yamaha MOXF-6, Casio MZX-500, Roland Juno-Di, M-Audio Venom, Roland RS-70, Yamaha PSR S700, M-Audio Axiom Pro-61 (Midi Controller). SOFTWARE: Mixcraft-7, PowerTracks Pro Audio 2013, Beat Thang Virtual, Dimension Le.