I was fighthing this issue as well.
I have configured for my parents a Dell desktop with an ATI video card (HDMI & DVI) and an onboard Realtek audio capbility.
I wanted audio and video to be available BOTH in the office (for working) and in the living room (next door, when using the computer for media viewing/listening).
To solve this problem, I *first* discovered the solution posted by capitano666:
- Open Sound panel
- Select Speakers as the default playback device
- Go to the "Recording" tab
- Right click and enable "Show Disabled Devices"
- A recording device called "Wave Out Mix", "Mono Mix" or "Stereo Mix" (this was my case) should appear
- Right click on the new device and click "Enable"
- Right click on the new device and click "Set as Default Device"
- Double click on the new device to open the Properties window
- Go to the "Listen" tab
- Click on the "Listen to this device" checkbox
- Select your HDMI device from the "Playback through this device" list
And you're done, the drawback is that you won't have a microphone selected as default recording device, but for what concerns me I couldn't care less.
But this wasn't enough for me. I had to open the Realtek HD Audio Manager application, click the SPEAKERS tab, and then click SET DEFAULT DEVICE.
Video is going to the living room from the ATI card's HDMI output, and to the office from the ATI card's DVI output, with desktop duplicated.
Now--THANK GOD--I finally have audio going to both locations as well. Living room over the HDMI feed (shared with video) and in the office on a pair of speakers using the "workaround" posted here. I haven't tested this with more than a L/R pair of speakers
in the office--I don't care--nor do I care about the loss of a mic... We only use a mic with Skype and, then, use the camera's built in mic for that app.
All solved, I hope!!
Dan