Amplifier
 

I have an Infinity 7520a two channel amp that is not being used. I plan on upgrading the door speakers to 6.5s in the future and adding the rear speaker kit. Is it possible to power the doors with the Infinity amp and the fronts and rears with the stock hifi amp? I thought I read on here that the stock amp has built in crossovers, so it might not be possible to power the PNP rear kit with it. Any thoughts? Here are the specs for the amp:

http://www.crutchfield.com/S-YZOv5osdgx5/cgi-bin/ProdView.asp?g=120&tab=features_and_specs&i=108R75 20A#Tab

You probably have a 4x40w Amp. installed in your car. It powers your front and door speakers. If you install rear speakers they would get their power from your Head unit. You could install that other amp, but would require wiring modifications.
John

I know that the rears are supposed to be powered by the HU, but after researching the subject, its only like 18w of power, compared to the 40wx4 stock amp. I would like to run the subs (door) speakers with the more powerful Infinity amp and run the others with the oem amp. I could get the 40wx6 oem Porsche amp from a 911, but was just wondering if I could use an amp I already have lying around.

PNP sells a 2 channel amp to power the rears because the HU is so weak. I don't see why you could not run the doors of a 2 channel, and run the rest of the stock 4 channel.