I'm not sure how Win7 works as I haven't received my copy yet, but it's very possible it works just like Vista. Go to control panel/sound and make your speakers the default audio device. This means anything soundwise comes out of your speakers or the headphone jack of course. Have foobar use wasapi in exclusive mode and you will get exclusive use of whatever output you have told foobar to use; like your dac. Both at the same time.
I listen to music with my phones connected to my usb dac/amp while I surf the web (like right now). I can listen to videos or music or any other sounds from websites (or any other program running) at the same time I'm listening to tunes. In fact, if I don't put my tunes on pause, I will hear music from the headphones and whatever from the speakers. Often I will browse my favorite new music sites where you can legally download new music (usually low bitrate mp3s) from artists, I guess hoping you will buy the cd. I pause what I'm listening to, sample the new song, start the download, then go back to what I was listening to.
Again, tell the system to default to speaker/headphone jack. Tell foobar to use wasapi exclusive to whatever output you want. These both can exist at the same time. I used to use asio or kernal streaming before wasapi made them unecessary (unless you're still using xp)
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