[JohnM]

Yes, use the L/R outputs. You will only be able to send signals to the left & right speakers and sub, I don't believe the Denon has any facility to route a signal from the L/R input to another speaker. If the Denon has bypass inputs for all speakers you could connect the REW signals to the various bypass inputs in turn and measure other speakers that way, but bass management may not be applied to the bypass inputs.