man my boy had 4 audiobahn 12s and they sound pretty horrible, just get 2 12s, and put them in a big ported box, tuned to your likeing, think about this 2 12s big box, 4 12s small box?
abp12t 2 12" bandpass enclosiure running off A800T audibahn mono amp at 400rms per sub 800 watts peak per sub. my sounds great, take a look at my page. not 4000 watts but sounding ggod.
Did you really just recommend audiobahns in a bandpass box and say it sounded great? I'm sure it gets loud but the two duals in a bandpass from best buy get loud. If your talking about sound quality stay away from audiobahn. Whats your price range everyone hear can recommend some subs you'll enjoy more than the a-bahns.