Sounds to me like you either have:
- blown/almost blown speakers
- blown/amp channels
- wires touching somewhere
When you said you moved speakers around so you knew it was a setup issue, what did you do? My assumption is that you swapped a right and left speaker and the problem stayed in the channels - not with the speakers. If so, then you can eliminate the first issue pretty much. The center channel could be something as simple as not having it enabled in the setup menu.
For the fuzzy,low channels and the center:
Here's what I would do.
1. Make sure the receiver is set properly, all channel levels to 0, all channels enabled.
2. Hook up just the center channel speaker. Make sure you have the wiring twisted tightly to form a nice clean wire if using bare wires. If not, make sure that if you're using spades, that when you tighten the lugs, that you're not twisting the spades around so they touch each other or are touching the chassis. Also verify good, solid, uncompromised connections at the speaker end.
3. Try playing a movie with known dialog to make sure you have plenty of good strong dialog.
If you get something now, then proceed to the front left speaker and repeat steps 2 and 3 above - making sure that there are no wires touching, etc. If you get nothing, unhook the center channel and see if it changes.
This may seem like overkill of babysteps but it's really the only way remotely to step through and identify the potential issues.
What kind of speakers are you running? Are they new? What kind of connections are you using?
