!?Car Stereo Help!? 04 WRX Wagon?

[scionized74]

i cant answer all the questions, but i can give some personal experience. i have a 1998 subaru outback wagon, i replaced the rear speakers with 6.5 in focal with a solid cone in the middle, the stock radio has enough juice to power those speakers plus the front. it really all depends on what you choose for components. as for a sub setup...i would go to best buy and they have a sub box for a 10 inch. i would use a " Kenwood - 10" Single-Voice-Coil Subwoofer
Model: KFC-W2511 | SKU: 8226626
Handles up to 1000W peak power (300W RMS) long-stroke design; 43.3-oz. ferrite magnet"

as for the box, just research on what would fit well in your car with for whatever sub you decide to choose, if you choose the one that i have suggested. i would also recommend this amp.

Kenwood - 500W Class D Mono Amplifier with Variable Crossover

the reason being is because the sub operates at 300 watts rms at 4 ohm impedance and this amp for the 4 ohm impedance puts out 500 watts rms.

 

[CBacc]

Looking to install an affordable car audio system, first timer. Advice appreciated.

I want to install an aftermarket stereo in my car, and I could use some help. I'm looking at an JVC KD-PDR80 receiver and a JL Audio C5-650 6.5" component set to replace the front speakers. My plan is to replace the front speakers and the receiver first, then move on to a sub and some rear speakers when I can afford it. I listen to a lot of heavy metal, and a fair amount of rock, rap, and hip-hop. I'm thinking just like a decent 10" sub in a box is all I will really need...
QUESTIONS: A) Will the system sound good with no rear speakers? It seems to me that even on my stock system the rear speakers aren't doing very much. Maybe that's just because my sound quality is crap and I'm always in front but if I can get away without putting any speakers in back that would be great.
B) The Receiver I like is 20wx4 RMS. The speakers are rated at 25-75w RMS. Obviously I will need an amp, right? The RMS power from the receiver will either not power the speakers or it will under power them which I understand can be dangerous. I'm wondering if I can buy an amp that will be able to power a sub in addition to the component speakers, or if I will need to buy separate amps for both the amp and the other speakers? Suggestions on specific amps for either scenario perhaps?
C)If I need to buy two amps maybe I can save myself some money with different speakers. Are there 6.5" speakers that will sound good without the use of an amp, simply running off the power from the receiver? Am I reaching a bit too far with the JL speakers? I don't need a sick system, just something that sounds good.
D) And finally I'd like some suggestions on a sub. I don't want to take up too much space and I can't afford anything custom. Just something that sounds good that I won't have TOO much trouble installing myself.