Sundown Z15 for sale. $160 shipped contiguous United States. (Does not come with box).
Rated for 1,000 RMS, could probably take more. Dual 2 Ohm. Sundown's website has all the specifics on enclosure size etc.
SQ sub, yes it gets loud and all that but it's made to sound good and it does. The box I have is about 4 cubes, and is for pickup only (Southern NH), in which case the price for both is $200. One of the pictures the box in the trunk of a jeep grand cherokee. So the box is pretty large. I can get dimensions if anyone wants them. The Sub is in great condition, bought about a year and a half ago, only spent 9 months in the vehicle.
Paypal or pickup. No trades, and sorry guys, I won't ship first.
Edit: More pics. Also, it was run on a US Amps 2000d (1000 watts at 1 ohm). Don't have an amp here, so I can't get coil readings.
More pics: http://imgur.com/VrOrH&CmZPz