Re: Confused - RCA output
With that deck you've only got 2 sets of preouts. A front Left and Right and rear Left and Right. You can change the REAR output to subwoofer and it becomes a NON-fading output. If it is set to rear it will fade just like a normal rear preout. What you're trying to do is run rear full range speakers AND a subwoofer. Since this is a lower model and doesn't have a 3rd set of preouts for a dedicated rear and dedicated subwoofer set of outputs you're going to have to install it as follows:
First start by setting your rear RCA outputs to REAR(fullrange) operation. You say you have a 4 channel amp. Ok, get 2 rca Y-splitters (1 female to 2 male) if you can't internally bridge the rca inputs on the amp. Run one right and one left to half of your amp. Then run the remaining right and left RCA to the input on the other half of your amp. Now, I'm assuming you're going to bridge this half of the amp for the sub. If so it is only going to sound good if your amp has an internal X-over. You could set that half to low pass and you won't have to worry about mid and high frequencies getting to your sub.
My suggestion would be an outboard electronic crossover in the trunk then you could run your entire system on 1 set of preouts and only have to run 1 long RCA cable to the trunk. The rest of the sytem would be short RCA runs from the trunk mount X-over to the other amps.
I hope I helped atleast a little bit.
Source Unit: Pioneer P9 combo
Tweeters: CDT DRT-25 Silk
Mids: CDT ES-5 (5.25")
Midbass: CDT M6 (6.5")
Subs: Pioneer TS-W12PRS
Mid & Tweet amp: Pioneer PRS-X340
Midbass Amp: Pioneer PRS-X720
Sub Amp: Pioneer PRS-X720