I have a Harman Kardon AVR 3550HD and have recently hooked up a new PC to it via HDMI for video and 6-8 channel analog for audio. All works great but I'd like to get the sound out through the HDMI to get rid of the analog audio cables. The problem is that when I try to set the HDMI port connected to the 3550HD as the audio device in Windows, Windows only allows it to be configured for stereo - surround sound is not available as an option.
A bit of research on the web indicates that Windows looks at the capabilities of the device the HDMI is connected to and will offer surround only if the device supports it, so apparently it is seeing the AVR 3550HD as a stereo-only device. I did find something that said this can happen if the AVR is set to pass the HDMI audio through to a TV with stereo speakers, and the 3550HD does have that option, but I have it disabled.
One other thing that may or may not be related is that when I click the "test speakers" test in Windows with it set to use HDMI there is just a little squeak from each of the front speakers, whereas when I do the same over analog there is a tone lasting a few seconds on each speaker.