I would say the only option is a P/A style tapped horn sub. Best output for music, just get the biggest one you can afford. Then shop around craigslist for some old school massive speakers with decent efficiency. You can usually find a pair every now and then for 50 bucks. Get 2 pairs, put 1 in each corner with a cheapy AVR that has a lfe or sub out. Going to be over budget, but cheapest option you got for what you want. Also, start saving cause you'll want another sub when you see what they do.