sound pressure level vs sound quality... i built my system for sound quality.. which is why i went with smaller subs that have tighter bass... the bigger your subs are, usually the sloppier the bass will be (although high quality large subs still produce very tight bass) cars you see with walls of speakers (like rickster's) are built for sound pressure level... biju is building his system for sound quality.. speakers aimed, boxes tuned, equalizers, etc.. generally sound quality systems dont get as loud... but they are crystal clear (although i think biju's will blow out eardrums with crystal clear sound..)