Do I need an external amplifier?
 

I'm purchasing the PPI kit from Harvey, a pair of Sony 6.5"s for the doors, and the MB Quarts for the dash. I'm also getting the AWIC-D3 head unit, which outputs 4x22 RMS. Do I need an external amplifier?

BTW, my MY is 04.

Definately add an external amp if you can. It will just make your system cleaner. You will add better power and possibly adjust the frequency sent to the speakers if the amp you choose has an electronic crossover. This will give you better sound at higher volumes and less distortion from unwanted bass in your smaller speakers. You dont need anything super fancy.. Just a nice 4 channel amp to add. It will make a big difference!

http://www.crutchfield.com/S-TZwmI1FDjEO/cgi-bin/ProdView.asp?g=120&I=236TC4004

Here is a good example... 50 watts X4.. MTX makes a decent amp and it is under $300.00.
Alpine MRP-F250 is another nice piece for $200.00 40 w x 4 with built in crossovers.

Best of luck!

How about the stock HAES 4x40? Fits nicely as stock item option.

So I only need a 4 channel amp?

I was under the impression I needed a 6 channel....

4 Channel is fine, even 2 channel is fine if you're not powering rear speakers. The factory amp is rated at 40x4 but is really rather underpowered. A good amp will help your system tremendously.

Patrick

Keep in mind that you can't talk about the amplifier being underpowered without considering the sensitivity of the speakers. With a high sensitivity speaker like the Infinity Kappa the 40W from the stock amp is plenty of power.