In my quest to be able to hear myself on stage, could I (Mark iv) keep my C90 plugged into the 8 ohm socket and plug a 8 ohm EVM 12L ext speaker into EACH of the two 4 ohm sockets? ie, 8 + 4 + 4. I could then use one of the EV ext cabs as a monitor down at the stage front! Then perhaps, I...