This is practically brand new. I've had it since christmas. In pristine condition. It simply blows the ultras sub out of the water. I had it hooked up to the ultras sub via sws jack. Worked like a charm. If you want something more powerful than a standard sws sub, this is it. It retails for $500. I'm selling because I'm getting out HT. Selling all my speaker gear to fund future headphone gear. I'll let it go for $235 plus shipping. I have heat under my name and feedback at head-fi.
*EDIT* The sub has a 250w amplifier built in. The continuous power is rated at 250w, max burst at 550w.
