I just purchases a Polk Audio PSW505 12-Inch Powered Subwoofer from amazon.com on 12/06/2012 and received it got it brand new. Set up everything using the low freq input and it was working fine. I have been running it a low to med volumes to ensure a even break in of the sub. Hoeever yesterday when I turned on my stereo the sub would npot produce any sound. I have checked the amp and all wires the led light in back of the sub is turning green and yet there is still no sound? I have no idea what happened or what i should do please help!