Sorry this long, but I'm trouble shooting a problem with the setup...
I've noticed that vocals and other sounds are slightly offset to the left, and the center imaging isn't as tight as I would have expected. The room setup is symmetrical, the speakers are equidistant from the listening position (+/- 0.1"), and the speakers are toed in equally.
This morning I measured the speakers with Omnimic, and beginning at ~800hz the right channel is 4db lower than the left channel. Other then the shelved lower output above 800hz, the frequency responses or nearly identical, and distortion measurements don't show any point of concern. The polarity is also correct for all drivers.
I have also reviewed the crossover, eq, and input/output level and gain settings in the harman software and they all appear correct. I checked the manual input attenuators on the back of the amp and they are all set to the 0db position (maximum input level).
I'm now going to swap the left and right speaker wiring on the amp to see if the problem switches speakers.
I don't want to jump to any conclusions about a bad amp module... Any other suggestions of what I should try next?
I also have what I presume is a ground loop issue that I've greatly improved- but not eliminated. I've turned off all dimmer switches, disconnected all inputs, tried swapping outlets, using a single power strip for the AVR and amp, etc., and just cant't get the buzzing noise to go away completely unless I disconnect the AVR. The buzzing also gets much quieter when there is no signal coming from the AVR. FWIW, using the same outputs/cables I have no buzzing issue when using the 708p.
Ah.... the joys of incorporating new equipment into a system.