Hooking up a 2nd amp

I'm about to have Best Buy install my RF sub, amp, and headunit from my old car into my new Avenger and was wondering-it possible to hook up the stock Infinity amp as well as the RF amp to my headunit? I want the Infinity amp to just power the speakers and the RF amp to just power the sub. My headunit is a Pioneer DEH-2500 and I have no idea what's on the back of it as far as pre-outs and such. Any help will be greatly appreciated, thanks.

If you only have one pre-out you can simply split it to both amps. The drawnback is you will have to spend time "tuning" the amps and radio. You will just have a volume control. No turning the sub up or down. Before you get the work done see about getting a radio with a seperate pre-out for the sub. You will then be able to turn up the bass while riding down the road.

I don't know if you had them hook the amps up for your avenger yet but I'm assuming that you were talking about the infinity amp that comes stock in the avenger. That amp is inline with the normal speaker wires leading from the radio to the speakers. Here's the problem, if you don't convert your audio to line level before the amp, you can eventually damage the amp. Your aftermarket radio is probably kicking 50Wx4 to you speakers (or something close to that). That amp isn't made for that kind of power. Go back to best buy and ask if you don't know already. If they didn't install a line level converter or they didn't bypass the Infinity amp then make them fix it before it does damage.

Hit me back when you find out what's going on.