heres a crappy vid of my 2 powerbass 15's on a test track, last 5-6 seconds are 10hz, i think i FRIED the mic on my camera....lol YouTube - 2 15" powerbass subwoofers hittin 10hz
oh, and yes btw, thats my ENTIRE backseat...lol, but believe it or not that box JUST fits in my trunk, i built it about 3 months ago, it sounds alright, but i want to build a better one