I appreciate the suggestions. The way the sub is connected, the receiver is in control and negates the phase switch (I tried it - it just turns) and the crossover (another knob). The AC cable is OK - I've got a green light. I agree that the hardware crapping out is not a likely cause.
I think my only options are to:
1. Recheck all my connections
2. Fool with the placement some more
3. Failing a solution with 1 or 2, just start over and pretend like I'm connecting from scratch.
If none of that works, I might need to call SVS.
