Car audio question

[NaughtyusMaximus]

As some of you probably know, I recently bought a new head unit for my car. It is a Kenwood KDC-415S. Right now, I have the unit set up normally, with the leads on the back of the unit going directly to the speakers. The unit also has (in addition to the leads) four RCA outputs (Front: L/R, Rear: L/R)

I am considering moving my sub over from my old car, and along with it its own amp and crossover. I don't want to have to bother making new leads through the car in order to run the speakers off of the Sub's amp as well, as they are fine running off of the head unit's internal amp. So, what I would like to do is just run my RCA & remote wire from the head unit to the amp, and leave the rest of the setup the way it is. My question is basically - will this work?

 

[bigshooter]

They are running fine now, but tehy should sound hella better if you run them off the amp. CLEAN POWER!(I love that term)
Oh yeah, it should work, do you have an rca dedicated to sub out?

 

[bobtist]

Yes.

 

[NaughtyusMaximus]

Hrmm.. I just set it up (outside the car so I didn't have to worry about hiding the wires, mounting.. etc.) and it does work how I described, but the volume of the amp isn't enough higher than the volume of the rear speakers. So it looks like I'm going to have to add at least the back speakers onto the amp. I think I'd like to do the front speakers as well, but I'm not sure if all four channels on the amp I have work.