We do outdoor movies in the summer. I have outdoor speakers set up through my Harmon Kardon receiver. In the past I have always played the movie through a dvd player and run an s video out to my projector and the audio to my receiver. I now want to play a movie from my computer. I have the HDMI connection from computer to projector but can't seem to figure out how to get the audio through my receiver so I can use the outdoor speakers. Any ideas/suggestions? Thanks!
TOSLINK or your analog-outs can pass multi-channel 5.1 PCM audio from your computer to your receiver -- my experience with digital coax (RCA) from your computer to your receiver is that it is limited to 2.1 audio.
HDMI/S/PDIF/Optical and etc because of copy protection you will need a device to extract the audio portion out. Only one digital signal is allowed. Without knowing the models of your setup, it's hard to give you more information. Analog doesn't have those hassles of copy protection.
You should be able to connect the PC analog audio output (set to 2.0 for the outdoor speakers) to the receiver. You will probably have to set the PC to not output audio via HDMI in the video or audio controls. No advantage using digital outs if you have them since you don't have center, sub or rears outside.