I just picked up a peavey combo 300 bass amp off craigslist. Before I even plugged it in, I took the 1502 black widow out of the amp and took the magnet off. I checked the foam and it is fine. I ran a piece of tape in the magnet groove. Everything looked good except there were some small marks on the voice coil. I put it back together and plugged it in. When I play at low/medium volume there is a scratchy sound. When I press in down on the cone there is no noise or scratching. There is no scratchy noise at low volume. Here's a pic of the voice coil. There is a small black mark and some small white marks. the big white mark is just the flash from my camera. Is it bad? any other ideas what the scratchy sound is? Thanks.