This will ensure you won't
ever get 5.1 in anything but films....confused? You will be!
Its a hard subject to tackle, but i'll try and keep it simple.
An amp receiving a signal over digital has to be encoded in some way. When you watch a film the audio has been recorded in either Dolby Digital or DTS and will be 5.1
The amp simply takes this data and decodes it into its individual speakers.
This is what we call 'pre-encoded' sound. The data is already set out and no additional data needs generating. The data is also compressed.
With music and games, this is different.
Take music for example - 2 channels of sound. This can be sent over the digital link no problem, but will only come out as 2 channels when its decoded.
If you wanted to take the 2 channels and upmix them, that's not particularly hard to do and Creative soundcards have done this for years and years. Heck, my old Live! card could do it
The same goes for games. Sure, it
generates 5.1 sound, but the card can not
encode it into a 5.1 stream the amp can understand:
The issue comes about how to transport this data to the amp. Why not just encode it to Dolby Digital I hear you cry? 2 reasons
1) Dolby Digital encoding in *realtime* is fairly heavy calculation wise. You need dedicated hardware to do it as far as I know. I would assume the X-fi is powerful enough - which brings us on to the next point
2) Licensing. To encode the data to Dolby Digital so the amp can read the 5.1 stream requires a licence from Dolby Labs. These are expensive.
So in short: If you want to encode 5.1 in realtime (so you can use digital out to your amp) you need a card which can support D.I.C.E (off the top of my head I think its Dolby Interactive Content Encoder). The most two well known are the nForce 2 soundstorm (which I'm guessing is out of the question
) and the newer Auzentech cards which have this feature.
You can not do this with your current card and connect it to the amp to get 5.1 in anything but films / pre-encoded content.
This lead Creative to make its own standard. Have you ever seen the Cambridge speakers have their own type of digital-in DIN socket that link to all Creative cards? By using their own transport stream to the amp, they don't have to pay royalties to Dolby/DTS. Sadly this can only be found on Cambridge amps are far as I know.
With these you can happily listen to 5.1
So in short, you either need to
1) Get a card that supports DICE
2) Connect it up via analogue and use Creatives CMMS to upmix everything to 5.1 (which works really well
)
Hope thats clear enough
(I really should make this a sticky
)