OK, so i'm stuck between a rock and a hard place. I don't know which subwoofer to get. I'm currently running two 12W7's, and although they get loud and sound awesome, they're just not where I want to be.

So my mind was sold on the GTI's which I have never heard in person, but for all research and reviews, pointed to them as being one of the premiers in SQL. I'll be going from 2 12's to 3 12's maybe 4 if I can get a great design. This is for a dodge charger. They are rated at 700rms, but from what i've read, they're severely underated and can get up to about 1200.

Now the problem... I sat in a magnum yesterday.. Has 4 12 cadence daytonas in a wall. Loudest thing i've heard since I had an opportunity to listen to 4 Atomic APXX 18's in a red truck in tallahassee. Not to mention, the sound quality within the car was amazing. Outside the car as well, but couldn't focus on SQL outside the car as I couldn't get over how loud it was. They are rated at 1500 rms. He had 6k watts combined on em all is what he said.

So all things considered (electrical up to par, with 3 batteries(Dekas), alternator(DC Power), amp (DDZ1 -- thanks to Schutte) which direction would you guys go for 3 or 4 12's? I know he had a wall, and I can't necessarily get a wall in my charger without losing my back seat, and I need my backseat.. But, I'm looking for SQL not SPL, but I want it freaking Loud as well. Both speakers are in my budget, and I know about the LMS, (out my budget), the Fi Q (too common among car audio people now), the RE XXX ( I want three or more speakers, enclosure would be too huge for my trunk).

At this point, without having the ability to hear the JBL's.. I only have the opinions of those who have, which are you guys.