I've been running numbers on doing a sub $200 DIY subwoofer and i think i've made me decision and ironed out my design. I'm planning on using a Swan 305 driver, 150w @ 4ohm PE plate amp, and a traditional enclosure made of 3/4" MDF. It will be tuned to 24hz using a PE 4-5/16" Adjustable port at 7". The internal dimensions will be 22.5" x 22.5" x 22.5", 11390.625 cubic inches, 186.7 L. I've calculated all this using WinISD. It looks fairly flat until it drops below -3db at 23.9hz. Does anyone see any flaws, or have any suggestions before i start construction? I know a sonosub might be a little easier to build, but finding 20" tube in a short length has proven impossible, plus cost wise, a full sheet of MDF is much cheaper. Also, i don't have to build a box for the amp. Also, i can get the MDF cut for free at the cutting stations at home depot or lowes. Now all i have to figure out is how to cut my holes for the amp, sub, and port. I may wait until i can get home to kentucky where i have all the necessary tools, but right now i'm in atlanta at college, so if there's anyone in the atlanta area who would like to swing by georgia tech w/ a router, feel free to (or i can come to you)! Any feedback would be great. Thanks a ton!