Originally Posted by Uncle Nick
It's not as simple as setting the speakers to 5.1 in the control panel and then selecting "Digital Output only" is it?
The 5.1 Live series had these options, so I assume that the Audigy will too
The official spdif format can only support 2 channels of PCM (PCM is uncompressed sound). Creative have a custom solution to support 6 channels of PCM, but of course that only works to their speakers.
Basically, for multichannel sound to work in PC Games, you either need a sound card which will compress on the fly to Dolby Digital, or a amp/speaker set which has a full set of analog inputs (commmon on speaker sets biased towards the PC market, and of course on higher end amps which like to have every conceivable connnection type).
To be fair, the analog approach is better quality. Compressing on the fly to DD to be decompressed a fraction of a second later is a bit silly quality wise.