I have 2 1960a 412 cabs. 1 sounds great the other very tinny or thin, not much bottom chunk at all. I am comparing the cabs 1 at a time using my TSL 100 head. I pulled that back to make sure they both had the same speakers in them they both have the correct Celestion G12T-75's. One cab is 1999 the other is 2001 - I do not think the drastic sounding difference is normal. I have to put Bass on the TSL to max to make it sound decent. The only think I can think of is maybe the jack plate is causing it? I don't see much that cna go wrong with it. I tried both mono jacks and stereo and no change. Any other ideas or has anyone had the same issue with a bad jack plate? Any pointers would be appreciated.