I did 145 for about 500.00. I'll be honest though, in a burp box, you could easily do it in a crx. Wait until some idiot sells a nice sub for nothing on craigslist. Do the same for a 1500+ watt amp. Right now you might have 300 dollars invested. Buy some big aeros off of here. Now there's maybe another 50.00. Buy your wood and build a crx box. There is another 50.00. Buy your wiring and a cheap head unit that uses usb another $200.00. There is your 150 after you learn how to find your peak freq and tuning, shave off the port until the two overlap and bam. $600.00 competition system.