L7's are pretty freakin' loud.
But, everyone one I've ever heard sounded like an amplified fart.
Based on my experiences, they are the worst sounding subwoofers I've heard to date.
My friend has 2 L7 12's tuned to about 40hz in Bronco, and they are LOUD, but they sound pathetic. All the people at my job, myself included, say both were just slightly louder to the ear than my one Crystal x2 15". And everyone agreed my sub sounded WAY WAY better.
Crystal baby!
Anyway...I've heard L7's on about 3 or 4 occasions, and every single one of them sounded HORRIBLE, even sealed. IMO, they are peices of garbage that should only be used for SPL purposes. Plus, some friends of mine said their corners have worn out.
IMO.. Kicker L7's = Worst sounding sub ever.