You're all missing the point. It is NOT THE SPEAKER! The speaker works FINE on other channels, other speakers work FINE on other channels, and ALL the speakers crackle and don't work on the center channel. By speakers, I'm referring to the 100W Sony speakers it is supposed to work with. They are 8 ohm satellite speakers. I did have a 20W 4 ohm subwoofer speaker from a dead set of PC speakers lying around, and hooked it up to the center. It did "work", but was distorted. There was actually sound coming out of it and you could understand what was being said, so I'm thinking it may not be putting out enough power for the 8 ohm speakers.
I swapped out every set of transistors and nothing happened, so the output transistors appear to be fine. What else could be limiting the output of an amplifier. I'm also fairly sure it isn't the digital decoder/tuner/output mixer/selector system because at low volumes with a 4 ohm speaker, the center channel seems to work fine (higher ohm speakers and higher volumes either don't work or are distorted while other channels work fine).
I'm thinking it may be a capacitor, but now I've run out of ideas so I'm just guessing.