Hi Grant,

It all depends what you're after, and what your budget is.

If you're after sound quality

(SQ), then a good set of 6.5" components

(6.5 inch bit goes in the doors, tweeters go in the little triangle bits) and a 10" subwoofer driven by either a pair of 2 channel amps

(bridge the second for the sub), or a 4 channel amp

(again, bridge 3+4 for the sub) will do the job nicely.

If standing outside your car with enormous ear bleeding amounts of bass is your thing

(Sound pressure level

- SPL)

(why!!!

) then you'd be better with a couple of 12" subs and big amps to drive them.

Your box needs to be the right size for your sub, the manufacturer will give a recommended sealed or ported enclosure size and you need to get that volume to get the correct response from the system.

A worthwhile investment is soundproofing.

.

.

a bit of a PITA to do, but cuts out that road/engine/exhaust noise

(if you want to hear your exhaust, open the window

)

I've gone for a SQ system, with a Becker Mexico Pro head unit, Becker CD changer, DLS A5 3 channel amp, Focal Utopia 165 components and an Aliante 10si sub.

Not fitted it yet!!

This forum is very useful:
http://www.talkaudio.co.uk/

Cheers,
Jon