Dazzle DVC100 audio in XSplit

in XSplit, click on your Dazzle DVC100 item in the scene list and hit Settings (or right click on the Dazzle in your scene view).  For Audio Input choose "Dazzle DVC100 Audio Device".  For Audio Ouput choose "Stream Only".  The volume slider at the top will let you adjust the volume of the Dazzle.

Now the important part:  At the bottom click "Configure" and choose "Cross Bar".  Under "Output" choose "Audio Decoder Out".  Then under "Input" choose "Audio Line In".  If you weren't getting any Dazzle audio chances are it's because Input was set to blank, which happens by default sometimes.  You may find that after you restart your machine the audio stops working (because Input resets to blank).  If so you need to come back into this dialog box and set Input back to Audio Line In.  It's just a bug with the Dazzle driver.

Exit out to the main screen of XSplit.  Click the gear icon next to the volume sliders.  Make sure under "Microphone" you choose your mic, not Virtual Audio Cable, since you should no longer need VAC for anything.

Just a note that sometimes when your computer lags out, the audio for the Dazzle will start to desync.  If people in chat are complaining that the audio is out of sync, you can fix it by going back into the settings for your Dazzle (i.e. right-click on the dazzle object) and change "Audio Output" to "System Sound" and then immediately back to "Stream Only" again.  This causes XSplit's audio bus to reboot which should fix the sync problems.  Typically I do this at the start of every stream just to be on the safe side since I tend to leave XSplit open all the time even when i'm not using it.  Generally if you boot up XSplit each time you stream, instead of leaving it open, you won't have this issue.