Just a little comparison I did at my shop here, I got a fairly good sized ported box, tuned around 35Hz with a 15, I had a Lethal Injection 15" sub in it, put a SAZ-3500D on it and gave the sub all it could handle and OMG it was loud and sounded really good, but got pretty stinky, I know way too much power for it, I was just bored and wanted to see what it would do... I then swapped in my custom built sub that Sundown built me out of an old Konaki motor with a super heavy suspension just to absorb power for load testing, and it sounded like total *** in comparison to the LI sub and was not near as loud. I wish I had a meter to tell the difference in how loud it was, but I don't have one yet, however will be buying one this month (a termlab). I was really suprized at the LI sub. I think I am going to put 3 12" LI's in my caprice for a daily, with a SAZ-3000D or 3500D on them... Should sound nice and be really loud. Kudo's to Nick on the IA subs for sure.