Almost any relatively recent soundcard (past 3 years?) won't have a problem passing through a Dolby Digital or DTS signal using the Digital Output. This situation will occur with DVDs, and a select few games (I think Doom 3 is suppose to be able to output in Dolby Digital).
But if you are talking about anything else (i.e. regular games), the only soundcard that can do it is the Soundstorm which can encode everything to a Dolby Digital signal and then passes through to an external decoder (i.e. Z680 control pod).
Originally posted by: Zelmo3
My Audigy LS does 5.1 digital. To be able to use it, I just have to run an app that puts out 5.1 sound (such as movies) and turn on the PL2 Movie effect on the Z-680s.
The above has the same restrictions, only DD or DTS encoded material is actually 5.1. For games or music, only stereo would be outputted, turning on PL2 just upmixes to produce surround channels.
Step 5: Testing your speakers:
Once your computer has restarted, go back into the speaker settings. This time, click on the "channel" button. This will test all your speakers one by one. You should hear "front left"... "center" ..."front right" and so on, coming from each speaker.
That definitely shouldn't work...you should hear: "front left", silence, "front right", silence, silence. Unless Creative preencoded the test to also output a Dolby Digital as well. And that wouldn't really work, since any Creative set with their proprietary Digital DIN connection wouldn't hear anything for Front Right and Left speakers for the test.