[NoiSeeVT]

Why 4, you can go with 1 or 2 higher quality subs and likely get a lot more output. Remeber output is a factor of not only the number of drivers you have but also ensuring they have enough enclosed airspace to function properly. I have 1 JL 12W7 and it hits hard as it did in my cavalier (which also was in a trunk). In competition I was hitting 147.6db in the Cavy, so that probably is a fair comparison. Plus amplification has a lot to do with it, if you are serious about having some serious DB's youll need some big amps. To get a system with 4 12's that pounds and sounds good (sq) youll be spending about $5000 just on the bass end of your system and then you need to consider the front stage, that much bass needs a lot of highs and mids.

David