i just got 2 12" DC Audio Lvl 4 xl subs, i haven't competed since '98-'01 and back then i ran Kove Armageddons, the x and u models and thought they were big and nasty, they don't come close to what these little 12"s can do. i know they have level 5's but this was the first "big" sub i have seen in a long time, 54lbs, it was a pain to install i will say that. i got the dual 1 ohm coils and have them being pushed by a RF T40001bd amp at 1 ohm mono, not that it means anything but the birthsheet is 4500watts. i might have to mess with gains more but the subs do seem to reach their max pretty quick, now they are only 1500rms, and the box is tuned to 31hz and peaks at 38 in the car. sound quality is also very high, even when hammering them they still hold the bass nicely. so are they worth the money, yes and then some. so on a scale of 1 to 10, they are a 10, they sound great, are built great and got some mean spl to them.