my friend (the guy that owns the performance shop around here) has two MTX 8000 series 12s, polk audio all the way around for speakers and the infinity center channel for his set up. powered by two MTX amps and an alpine head unit. hit system is pretty nice, nothing overkill sound quality is excellent but we put it up to this girls car that has 3 MA Audio 10's and her bass was much louder and clearer then the MTX. ok so a 10 is supposed to resonate faster and clearer but at that level a 12 should hit just as well. im sticking with two 12s but im going with a DEI product. all in all i would stay away from JL and Alpine for subs, they make good stuff and thats why i listed them but you can get something just as loud and just as clear for half the price because its not "JL" they are like the oakley of the music industry, they think they are hot **** so they only distribute to this big corporate companies but there are other lesser known companies that are even better and just distribute to more people but lesser known people

 

ive heard personally:

JL W3s, W7
Image Dynamics IDQ
Image Dynamics IDMAX
Alpine Type R

 

do you need an amp to power whatever subwoofer you are gonna go with?
if so email me.. i have a audiobahn a1801q that does 560x1 @ 2ohms.
looks awesome and performs even better... has a digital voltage readout also...