The 880 has a setting choice of mono or stereo for the sub. Since it's going to a mono amp and one sub what is the difference and does it matter? Is it like everything else set it to what sounds best?
I Think if you were running a 2-channel amp for your sub that you were bridging then you would want the stereo signal coming from the Headunit to the amp so it can bridge the signals at the amp, but since you are running a Mono amp you should run it in Mono.
