Infinity tss-1100 sub problem
hey buddy, I have the same system, and although I haven't experienced it on this one, I had the Harman Kardon equivalent to the TSS-750, and the sub did this same thing. It was a loose RCA connection, and, as I was well outside of warranty, I took the amp out of the back and just re-soldered the connection myself. It now functions flawlessly for my bedroom setup. I hope you get it all worked out on your system! I can't imagine using this awesome system without its deep notes!