5.1 Sound through SPDIF on movies, but not games (HTPC)

[Krimsonsky25]

I have a Denon AVR 2112c connected to a 5.1 system, and connected to my PC (asus p7p55deluxe motherboard) using a Digital Optical cable. I have successfully watched many HD movies with 5.1 sound when i select it to output in SPDIF, I've also had no problems with the 5.1 system or the receiver when connecting a PS3 to play games/movies in 5.1. My problem lies with everything else that isnt a movie on the PC. I have read about possible needing DD live or DTS connect, but I dont understand why a videogame system from 2006 is able to produce everything in 5.1 when a motherboard from 2008 cannot. any help is appreciated, thanks

 

[astrallite]

PC games are produced with uncompressed audio. The programmers expect the users to have PC speakers and as a result, use the minijack outputs.

Video game systems are produced with Dolby Digital and DTS because the programmers expect the users to have home theater speakers.

 

[Krimsonsky25]

That sounds kinda strange. Why would developers design a game with 5.1 or even 7.1 just for the PS3 or xbox, then essentially down-tune it for PC? Some examples would be Crysis 2, Dirt 3, F1 2010, Grand Theft Auto IV, etc. Surely the games have these capabilities, they just need to be 'unlocked' on a PC, right?

 

[blackhawk1928]

I don't think your on-board sound card from the motherboard processes sound effects. I think the output is just digital stereo out. I could be wrong, never been sure, because I think your actual pre-amp on the denon should be processing effects. I'd like to see if anybody knows for sure.

 

[Krimsonsky25]

I've seen Creative labs advertise their X-Fi series being able to run DD live and DTS Connect, which may be the solution. Of course I'd like to know from a 3rd party first before dropping $100 on a sound card that might not change anything at all. Thanks Blackhawk and astrallite.

 

[ssddx]

i have the Asus Rampage III RoG edition motherboard which has an integrated soundcard. I have an evga gtx470 video card with dual dvi output. My receiver is a pioneer elite vsx-30.

i currently utilize the audio-over-dvi function that my video card supports. i use a dvi to hdmi video cable to connect up to my receiver. under my audio options i see my receiver listed as the default device if that matters. i have my receiver settings to advanced surround sound.

i know for a fact that i get "surround sound" from my back speakers during games and movies both. the only non-surround sounds are from windows itself and any online video/audio such as youtube.

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maybe you should look at the specs for the audio module i use. specifically to see if DTS/DD-L are listed. if they are then it may be your problem. if they are not then maybe your problem lies elsewhere.

 

[Krimsonsky25]

thanks ssddx, i did a bit of searching for the GTX470, and found small bits of info such as the GTX 400 series being able to run 8 channels over HDMI, and that SPDIF can only handle 5.1 or less, but nothing really led me to a solution as to why I got 5.1 over a movie but not a game. That would leave me to blame the receiver, but with the PS3 giving me 5.1 on both games and movies, it makes me want to blame something with the computer software for not outputting the right signal to the receiver for games and everything else. The Denon 2112c has basic sound 'modes' such as multi channel stereo, pro logic 2, etc. when it is receiving no sound, or sound that isnt specially encoded. When it IS receiving the encoded sounds, it will automatically switch to DTS or Dolby Digital, depending on what signal it is getting from the source.

The best example i can give is switching VLC media player's output from stereo, mono, etc. to "A52 over SPDIF", where the sound comes in at 5.1 and the receiver aptly switches to DTS. The receiver switches to DTS (or dolby digital, i forget which) as soon as the PS3 is turned on, so that entire system is encoded for 5.1 use (or at least making the receiver think so), even though some of the content isnt formatted for that.

It's looking like maybe I need to find a way to force the receiver to stay in one of the special 5.1 modes.