For a long time I have used a Dolby Digital Live sound card, that takes whatever DirectSound mix a game has and converts it to AC3 on a coaxial digital output. This works fine for my old computer and old 5.1 sound system. I've had success under both WinXP and Win7. (Note that this system has an older 3d card that does NOT support HDMI, so I use DVI + the sound card's SPDIF port.)
I have a new 7.1 sound system in another room and I will be building a new Win7 gaming rig to accompany it. I'm also deeply confused about what the best way is to get 7.1 sound out of Win7. My past experience has been that you needed either a rat's nest of discrete analog cables or sound hardware that produces a multichannel AC3 or DTS bitstream.
But I know that Windows 7 lets you choose from a variety of muli-channel speaker setups in the control panel, and people seem to be saying that now all you need is your motherboard's on-board sound, and you can get multi-channel surround sound magic with just the basic OS features. Can you do this over the motherboard's SPDIF port, or must you use a video card that supports all the right HDMI+audio voodoo?
If anyone can demystify this topic for me, I would be hugely appreciative.
ricemanva posted some great stuff in another thread (http://www.avsforum.com/t/1466936/pc-gaming-surround-sound-card-advice
) but I'm still quite unsure about what path the sound signal takes--SPDIF or HDMI. If you must have sound coming over HDMI then I assume that, as with all things Windows, some hardware/drivers will be easier to get working that others.