IMPORTANT: PLEASE SEE UPDATES BELOW, THIS INFORMATION IS NOT EASILY OBTAINED.
1. Asus G55 has two audio outputs. Analog (3.5mm) and Digital SPDIF (3.5mm adaptor on Toslink to Toslink). This is the ~same~ jack, it detects analog or optical digital depending on the cable.
2. SPDIF output only supports ~Stereo~ and ~Dolby Digital 5.1 Passthrough~.
3. This means: you will ONLY GET STEREO output in most cases through SPDIF, including in video games. What happens is that on the SPDIF ~receiver~ eg. amps, surround headphones, etc. The receiver will UPSCALE to 5.1/7.1 etc. using Dolby Pro Logic or other means.
4. You CAN STILL GET Dolby Digital 5.1 through SPDIF when it is "passthrough" ... That means from BluRay, VLC playback of 5.1-encoded AC3 files, etc.
5. For MOST GAMES, the output is STEREO, since it doesn't generate/encode Dolby Digital 5.1 ~on the fly~, unless you have "Dolby Digital Live" eg. using an external soundcard like Creative XFi USB.
6. For MOST GAMES, on your surround receiver/headphones you can choose "Dolby Pro Logic" or "Bypass". The surround receiver/headphones will still try to "upscale" to surround.
7. AFAIK this does ~NOT~ mean that games do not have "Surround" information encoded in them somehow, this is somewhat esoteric and I am not sure how the "Surround" sound is encoded into stereo channels, but this is part of technology that Dolby has... eg. Dolby Pro Logic encoding of "Surround" in stereo channels.
Hi all, you just need a 3.5mm to Toslink (or 3.5mm adaptor on Toslink to Toslink) to get digital optical out, ie. 5.1 surround, 7.1 surround and so on.
The headphone jack doubles as a SPDIF output as per the specifications.
I hope to add to this over time, if anyone can find test files, questions for games, etc... fire away...!
Dolby Digital 5.1 (7.1?) Test Files:
http://www.dolby.com/us/en/consumer/technology/home-theater/dolby-digital-plus-download.html
