I've got an Alpine 9827 HU that has front, rear, and sub RCA outputs. I'm running to a 4 channel amp and powering a set of comps and a 12" sub.
Obviously I run the sub output to the rear channels of the amp, and the front output goes to the front channel input of the amp. What do i do with the third set of RCA outs - the rear output?
Do I get a y adapter and combine the front and rear RCA out to the front inputs on the amp?
Do I just leave it alone and fade the HU all the way to the front?
leave it alone there is no way you can fade it anyway. Just run the front RCA's back and fade it to the front. What I would do is run them back anyways just tuck them away because in the future if you buy a new amp just for your sub you can just plug it in and change the wires and have the 4-channel for front and rear and amp for subs without having to take out the head unit again.