Friend is looking to buy a sub to put in the back of his Chevy Tracker, with a buget of $100. His goals are strictly output. He wants it loud... He has no idea what SQ is, so that's not an issue. He had 4 12" Wal-Mart Duals at one point and swore they were the best sounding things on the market. He listens to nothing but rap. I will be building the box, tuned to ~33hz for his musical taste. I'm not exactly sure the max volume I can get away with back there, but I know it's not much. I'm guessing a 12 will be the biggest we can go and still remain in optimal specs. He has a 600 watt amp to push whatever he buys @ 2 ohms, or 4 ohms bridged. What are suggestions as to what sub he should get for the $100 range?

You can get used Kicker equipment dirt cheap. I've bought and sold a lot of my Kicker stuff that has big numbers.

$100 might even get you a 400-600rms sub, if it's used and off the online classifieds.

Someone in the forum has a new SSA sub for $100 shipped, that seems like a fair price. 300rms.

Parts Express has a sale on subs. there looked like a couple that might work. Otherwise see what you can find from private sellers as stated above.

http://www.parts-express.com/wizards/searchResults.cfm?srchExt=CAT&srchCat=486