I currently have a 15w0 with sealed enclusure at 250W amp. it's alright but i think it could be better. would 2pcs of 12" subs with the same 250w amp make a big difference? i really don't know which one is better?! anyway, i'm also considering the space that it would take for 2 12" subs. my current enclosure i think has 1.5 cubic ft. i think 2 12" subs would have a bigger box. but by how much? i wanna be able to get the spare tire just in case. hope someone can enlighten me. thanks!
if you want more upgrade to the 15w3. you will get much more output from that. Or if your feeling really froggy go try to find a 15w6 on EBAY. that will slam the hell out of your car.