hey everyone. I am having a issue with a prosub 80. It was clearly damaged in shipping (I moved across the country). There is a slight damage on the back left corner of the unit but I don't think it has broken the case. When i pink the sub i get something that sounds like a geiger counter. Lots of pops and cracks. I attempted to open the unit but didn't really see any obvious issues. The cone looks to be in great shape. Also the crossover doesn't appear to affect the distortion at all. The volume knob on the unit still works. I have tried all 3 RCA inputs and I have checked the fuse. I feel as though a solder joint is loose or something simple. I have a solder iron and some nice silver solder so i wouldn't mind fixing this myself if I could. My gain stage is correct through out the stage and I have tried multiple cables from the receiver and multiple sources to the sub. Thanks.