They're great speakers, i've got a pair of 12's that i was using in the spring, they've got a lot of clean, lowend authority. They exaggerate lowend a LOT, if you're buddy likes rap, or a lot of way way low bass, that's the speaker for him.
The exaggeration follows through from 30hz or lower to the 40-45hz range, and after that, the bass is less extreme, per say, but is clean to the point where you'll have to turn off the subwoofer output to see if they're playing, they blent in flawlessly with the music, and just sound like your door speakers can play down to 50hz with ease.
Great great speakers, overall.
As far as power, i was underpowering my hifonics amp, but i'll bet they were still getting ~700w rms a piece, and were already pretty **** loud. I've heard of a lot of people being disappointed with them when only feeding them ~500w, tho, so i'd probably shoot for 750w rms at LEAST.
Later!