Im Looking for a cheap 12" subwoofer that can hit hard to replace my JBL's LC-S1200. So far I have found Audiobahn AW1251T 12" Papercone Stampe for 42 bucks at IkeSound. It needs to be able to handle 350W RMS at 2OHMS.
If you don't mind eBay you can get the Audiobahn cheaper ($50-$55 delivered) and Cerwin Vega HED-12DVC for $60 delivered. these are both dual voice coil models. I posted 30 minutes ago asking diff b/w single and dual voice coil. only 1 reply so far and it's not really on point. I picked up 2 Polk 12" Subwoofer Sub GXR GXR12 124 at CIrcuit City closeout last night. Only wanted 1, but w/ 2 you get free 2 sub enclosure. For $60 for the 2, I figured I'd sell one of the subs as well as the box on eBay and end up paying for the sub I keep and a single box. Not sure if I'll keep or return these (or eBay them and the box).
Audiobahn Aluminums are great.. my friend has a 15" with two memphis 1000 watt amps going to it and it is amazing SPL... not really well with SQ but its ok