Besides switching the default audio device, how can I send the audio from one Windows Store (aka Metro) app (say x-box music) to one audio device, and another (say the video app) to another audio device?
It is possible to enable the "Stereo Mix" recording device and configure it to replicate the output on a device of your choice.
This is the easiest way to do this. it's built into windows... just not very prominent.
So yes, there is a UI that does what I want, but it requires the correct kind of devices to work, and as far as I can tell, it only works over the network, and not with local devices.
If you have a suitable network speaker system, and sharing is turned on, then from the xbox music app, you can simply open up the charms menu, select devices, and select the audio device you want to stream to, and then everything plays just fine to that device.
See http://channel9.msdn.com/Events/BUILD/BUILD2011/APP-408T At 16:16, he demonstrates exactly what I'm wanting to do, but when I go to the devices charm, I get a message: "You don't have any devices that can receive content from Music".
Unfortunately Generic USB audio devices do not get picked up as a usable playback device.
I HAVE FOUND A SOLUTION at least to firefox:
This is a new Firefox addon waiting to be reviewed developed by a friend of mine:
I have waited this for years.
I wanted to use this when my wife is seeing youtube on her chrome and me seeing anything like coursera online MOOC lectures (FF) on the TV which is connected to the pc. I wanted to hear my classes on the headset and my wife on the speakers for youtube.
I have 2 mouses (one for me wireless) and have installed a neat program which called teamplayer which gives multiple cursors (each cursor for each mouse).
So I have now literally the capability of working 2 persons on 1 pc.
And on top of that it works seamlessly with "Enounce Myspeed" for speeding up the video lectures' playback.
This has been an issue since well forever. In Windows XP (in Vista to I believe) you could set your default audio device to #1 -> start a program -> switch to default audio device #2 and windows wouldn't update the default audio device for programs already running. So the program would keep playing in audio device #1.
This was however changed in windows 7 (or vista, can't remember) so now when you switch from audio device #1 to audio device #2, windows updates this change in all running programs, so the program will switch from playing on #1 to playing on #2.
There is still (10 years later -_-) no permanent solution to this, the one program that almost does this is "Indie Volume" the program is sadly quite buggy and often refuses to work after the first reboot after install (It does however work perfectly that one time after you install it -_-). This shows however that it is in fact possible.
There is a work around if you only want to split 1 audio source into 2 outputs in the form of the program VAC (Virtual Audio Cables). But no working solution exists that directs multiple programs (programs that lack a setting for manually choosing their output device) into multile outputs.
Be useful if it was possible. Kind of like multi-track recording, but for output. I doubt this is built into windows (think of how hard it is to do good multi-track recording), but maybe there is a 3rd party piece of software that can do it.
Now comes the research:
A windows forum suggests it is possible, by selecting a different output device in the app. Apparently Media Player can do this (and if you have a decent sound card so can Audacity), but neither xbox music nor video can do this.
I relise I haven't solved the problem, but maybe I've helped.
See here for more info on assigning different audio devices.
However, this forum seems to suggest it's not possible.
(These are Win7 posts, but it may be applicable to 8.)