find out today, here is the conclusion in the article of this sub, everyone please read full review:
Conclusion It almost pains me when I have only good things to say about a product after testing. Don't get me wrong; it's not because I'm some kind of scrooge and take glee in writing a damning review. Rather, when a product is this good you're naturally tempted to doubt your own evaluation process. After all, for the benefit of the consumer, your job as a reviewer is to reveal anything negative in a product. The UL12 really doesn't have any drawback in terms of speaker performance. It's surely the best subwoofer I've had the pleasure of auditioning. It played effortlessly across all genres of music with precision, never pigeonholing itself to one specific style of music. Its imaging was perfect, the impact striking. There was no distortion to speak of. The output was unapologetic and powerful with a capital P. The Critical Mass UL12 is that rarity in mobile audio, a dream product for BOTH audiophile and bass head. If there's any drawback, it's the price. But I'd gladly sell a few things to scrounge up the $1,999 price tag. It's worth every dollar.
this is what my frind got out of his. he sells the stuff.
in the 13W7 box tuned at 36 Hz it will do about 143 - 148.3 db in a hatch car with anywhere from 400 watts to 1500. I was able to squeeze out 154.0 db when I put 4000 watts on it in the same sixe box but it was tuned at 54 Hz. the box i used that time was the JUG12S.