If u need serious "boom boom" effect, I suggest u raise ur budget a little and get what Alien suggested (or even the z-680) but if u insist that's ur budget and don't mind a little less base, try X-530 it's really not bad at all. And it undercuts ur budget by quite abit too
Here's a breif review.
http://www.neoseeker.com/Articles/Ha.../Reviews/x530/