Upgrading subs

Ive got 2 12inch audiobahns now, but i want to upgrade to 2 more powerful subs. I have a JBL 600.1 amp. I would like to know if anyone has subs that they have been happy with that would be more powerful than my POS audiobahns. Im looking for any recomendations on subs. Thanks!03 F150 on 24's

HU:Pioneer DVD5700

Frt:MC57

Subs:(12)S12L7

Amps:(3)KX2500.1's, MC-2004

I'm reading your bio line: "Andy 2 12" audiobahn bandpass subs and 2 10" memphis in custom box in place of center console/4 three way pioneer speakers/pioneer unit/JBL BP-600.1 amp and 1200.1 /1.4farad capacitor/4 tweeters" Do you also have 2 10" Memphis in place of the center console? What are the 4 extra tweeters doing? You probably have all sorts of cancellation going on because you have subwoofers in different places in the car playing the same frequencies. If you want to keep the 2 10" Memphis subs in the center console, you should get something that can play really deep for your trunk and implement a proper crossover system so that the 10" and the rear subs aren't playing the same frequencies. Don't go bandpass. Try an Adire Audio 15" Brahma in a ported box. Feed it over 500w and use a 60hz low pass cross. That should kick the sh*t out of your audiobahn bandpass thing. Then cross the 10" in the center console from 60hz to 150hz or so. High pass cross your mids all at 150hz. Oh yeah, and get rid of the 4 extra tweeters. If you do all that your system should sound 100x better than I'm sure it does now. Actually, maybe 1000x better. New Project: 2003 Pathfinder