What I would like to know is what is the best performing subwoofer in the $400 - $700 range. I would like to get a subwoofer that can produce strong low base that you can feel and has a good db & spl rating. My thoughts on this is that I might be looking at a 10" or 12" subwoofer. My room is aprox 22' X 12' if that helps at all? My dream subwoofer configuration for some time was to run dual JBL 18" subwoofers if I was able to move into a bigger house but heck I can afford to build the subs anyway.