one of my speakers started cutting out at any volume and seemingly randomly. I discovered that by tapping the woofer cone it would come back on and work perfectly until it didn't. I was told that one of the leads to voice coil was detached. I thought I could fix it. I cut the dust cap off (carefully) and found that, of course I couldn't even find the wires so I decided to get replacement drivers. Confident I was on the right track. I replaced the drive and surprise! - same problem. Can anyone tell me what the heck is going on and how can I fix it?