We just bought this subwoofer a couple of months ago. At first it was working just fine, but last month, we noticed it was not. There is power, but no sound. We checked the cord to see it if was faulty, but it is okay. We tried to trouble shoot by reading both manuals (subwoofer and Yamaha amp) to see if something got changed - to no avail. Help please!! We called the store we purchased it from and they told us it was our own problem to deal with. If we didn't purchase their "special" in-store warranty - they don't want anything to do with you after you have walked out of the store. Polkaudio in Canada??