Well after a few months of planning and reading, i think i'm going to get the following:

alpine cd/mp3 head unit
alpine 6 1/2's for doors
audiobahn flame-Q 10" 900 rms woofer
sony xm-d1000 900 rms amp (no knocks please, budget)
stealth passenger box from subthump

Anyways, i have a few questions:

Is the 0.5 cu. ft. box gonna be enough for such a powerfull sub?

How important is it to have a capacitor?

What wires do you guys recommend for this setup?

 

The power of the sub has nothing to do with whether or not the enclosure has enough volume or not. Look up the manufacturer's recommended enclosure size for that particular sub.

Not very. A high output alternator is the answer. A cap is only good for when your stereo draws slightly more current than your charging system can deliver. If it is drawing more current than the charging system and cap together can supply it will do more harm than good.

RCA cables with "twisted pair" construction. Shielding alone is not enough to prevent noise from entering the system.

16 AWG (minimum) speaker wire.

4awg (minimum) power cables.