evga 680 sli built-in sound - optical output (can't get 5.1 output)

Play a dvd you should get dolby digital 5.1, but that's the ONLY time you'll ever get it.

i ran into the same problem...PC sound works differently than HT sound, this is assuming you have it hooked up to a HT receiver...you will only get 5.1 surround if the source your using is sending out a Dolby or DTS signal...for some sick reason on PC sound cards optical doesnt output 5.1 on any games unless they are actually capable of outputing 5.1.

so heres what youve gotta do...your gonna have to go and get a seperate sound card that supports Dolby Digital Live or DTS Live...i think its called DTS Live but not positive...anywho...get a sound card that supports that...it will basically "fake" 5.1 surround to your receiver on games and it wont be like having sound output natively in 5.1 but it will be pretty close...at least i dont think its the same, just doesnt have the same punch to it...heres some links to some cards that support Dolby Live

http://www.newegg.com/Product/Produc...82E16829118109

http://www.newegg.com/Product/Produc...82E16829156001

http://www.newegg.com/Product/Produc...82E16829271002

all 3 will get the job done...i own the Turtle Beach card and its just okay...definately nothing to write home about...ill probly be upgrading to the HT Omega striker...its the 3rd link...ive heard nothing but good about it.

Most games including those you listed do have true surround sound, but you cannot output it through the optical cable to your receiver. You can only get the surround sound from them using the multichannel analog audio outputs (3 - 1/8" headphone jacks). Therefore your receiver must have multichannel analog audio inputs (3 pairs of RCA jacks) to hook it up correctly.

Or you can get one of the sound cards that WaveyD4vey linked to, but as he said it's not quite the same. However if your receiver does not have the analog multichannel input then it is your best option.

The only type of sound that will be output in surround sound through the optical cable in your current set up is Dolby Digital or DTS soundtracks from movies that are passed through to the receiver. Everything else, including games and the speaker test you tried will only be received in stereo.

I know what you mean. Countless others have threads in here about the same thing. I expected to just plug the optical in and be done with it - even on a $300 Creative card! Boooo!

Dolby Digital and DTS are an audio format. Kind of like a file extension (.mp3 or .xls, etc etc). The output of games are not in Dolby Digital or DTS format, but in their own format. Their format only tells the sound card what speaker to play the sound on. In the case of a movie, it is already DD or DTS and all the card does is pass the signal. A card will need to have DD or DTS Live encoding to change the format of audio in games to something a receiver can play in surround. The Auzentech Prelude is an excellent card for this, which includes hardware acceleration like the Creative X-Fi cards.

So your only option is to either use analogue cables (~$15) or purchase a new sound card.

All of the sound card companies had a huge failure when they decided to have optical outputs, both in technicality and informing customers. It will only get worse when they decide to support HDMI.

i think its a total scam...they just want people to go out and buy something...a new sound card or a total new set of speakers...at least thats my conspiracy theory! but ya i thought the same thing to when i built my new comp about a month ago...then i realized i was only getting 2 channel audio which sucked hard!

i actually tried getting the splitters and and running it to my analog outs but i could never get my center channell or my left surround to be recognized...and i know it wasnt an error in how i hooked it up or the cables fault since i bought extras just in case...once again, i smell a scam!!!

id personally just go and get a card that does it for you...i dont think its worth the hastle or time...but it wont sound quite as good as if it were hooked up through analog...i guess its a trade off...i just got tired of messing with it.

This is nothing new, only new to you. Games have always required an addin soundcard with analog connection for POSITIONAL sound in games except for a few Nforce2 motherboard chipsets (2003) that had DD live and could be connected to a receiver with a single RCA type coax cable. You can connect the analog outs on the back of your motherboard but it won't be POSITIONAL in games. There are some newish sound cards with DDlive or something but I have never used one, just read the reviews. I picked up a used Audigy 2ZS off craigslist for $20 from someone that was "upgrading" and connected it to my 7.1 receiver with Creatives Home Theater cables ($17).

Isn't the reason that you cannot use a digital cable to your reciever for, say, EAX is because the reciever does not have the ability to decode the signal? If Creative were to liscense the EAX technology and allow the necessary hardware in the reciever then I would think that there would be no problem. Anyone know different?

This topic brings another question to my mind. I have been trying to get a handle on PC Audio...

If you use analog outs to your reciever (because you want positional sound in games) and you are watching a DVD with DTS, then does your signal now have to be processed by two DACs? One on the sound card to push the signal through your analog wires, then a ADC on the reciever before it processes the DTS, and finally another DAC before being pushed to the speakers?

If you use the analog inputs on the receiver then all the receiver does is amplify the signals from the sound card.
You will not get positional sound from motherboard audio unless you have an Nforce2 WITH Soundstorm. Not all Nforce2 MB had Soundstorm.
Nvidia leased the tech from a company (Sensaura?) then Creative bought that company and Nvidia could no longer use the tech. People were mad at Nvidia for not using Soundstorm on NF3 but it was not their fault.

Edit: Some games have switched to OpenAL instead of Eax. Vista does not use Eax from what I understand so Eax may be dead(?).
Dolby Digital live on a sound card will get you a SPDIF connection to your receiver and your receiver can process it then into DD, DD EX, Dolby Pro Logic whatever.

Is that right? What about the reciever applying soundfields and the like? I know my Yammaha does have a function (Pure Direct) that lets you pass on unprocessed sound, but I thought that was a feature that you had to enable.

This is true, but EAX would also have to output a digital bitstream so that it could be sent over a digital cable to the receiver. I'm not sure if it currently does this or not.


In this case your sound card is doing the DD/DTS decoding, and the output is analog, so the receiver just takes the analog output and amplifies it. There is no more DAC being applied other than the sound card itself.


Typically when using the multichannel analog inputs no sound effects or processing is applied, and usually can not be applied. The receiver just becomes an amplifer in this mode.

Thanks for the replies!

Many games use EAX though OpenAL. Vista simply does not support hardware accelerated DirectSound, which is why many game developers have switched to using OpenAL.


This is a common missunderstanding. EAX not a bitstream format like DD or DTS, it is simply an effects library of digital signal processing routines such as reverb and ambient occlusion created to simulate environmental conditions in audio mixes.

Audio Cards
http://techreport.com/articles.x/13874
I love charts

Very nice find!

That is what the article implies, but it is wrong. As I explained in my previous post above above; EAX is just a collection of digital signal processing insturctions used to simulate enviromental conditions. Any games that supports surround sound will do so with or without EAX support, you simply won't get the various reverb effects and such which are supported though EAX if your sound device does noth support the standard.

As for getting surround sound from games to your receiver, you can get uncompressed multichannel output from any sound devices analog outputs to a receiver wich supports analog multichannel inputs. Otherwise any sound device which supports supports real-time DD or DTS encoding, will give you the option of using those compressed digital formats.

The Prelude is the only sound card that supports both EAX5.0 effects as well as real-time DD or DTS encoding. Creative's cards support up to EAX5.0 as well, but none of their cards support real-time DD or DTS encoding. Other cards not made by Creative labs only suppor tup to EAX2.0, but several exsit which support real-time DD or DTS encoding.

EAX simply isn't what tells the sound device which sounds comes out which speakers, it only adds effects to those sounds. For instance, if a game developer wants sound to echo like you are in a cave, he can send an EAX call to have the sound hardware add reverb to the sounds to simulate what things sound like within a cave. Or perhaps the devleoper would like sounds emanating from behind walls to sound muffled, EAX supports calls for that too.

As for the 3 stereo mini-jacks, that is how you get uncompressed 5.1 analog audio out of a PC.

The sound engine in the game is what determines which sounds go out which channels and to what extent, and it does so by interfacing with the hardware though an API such as OpenAL (or DirectSound, which supported hardware acceleration prior to Vista). Again, EAX nothing more than library of DSP functions that are called on by a game's sound engine to add effects to those sounds, it has absolutely nothing to do with the actual possitioning of the sound.

In my research, hands down, for gaming the Auzentech Prelude on a HTPC is the king right now. The only issue is price. All the special reverb and game effects like EAX (using Alchemy if needed) are converted to a DD signal for your receiver. Future drivers are also supposed to support DTS Interactive, which does the same thing except it's DTS not DD.

Supposedly Auzentech is releasing a HDMI add-in sound board which will allow you to run only one cable for both audio & video. This would mean lossless TrueHD as well. Just a rumor from a few in this board though.

Yes, I have a Sony V333ES receiver and a blue light comes on when it's getting a DD or DTS. It also tells me what kind of signal it is on the readout (Dolby D [3/2], DTS [3/2/1], PCM [48Hz], etc etc). I would take a pic but I'm at work. I was stoked to see it say Dolby D when I enabled the DD Live checkbox. The sound is incredible. I noticed an improvement in sound quality over the X-Fi Elite Pro (which I returned).

http://en.wikipedia.org/wiki/DirectSound
http://en.wikipedia.org/wiki/Openal
EAX: http://en.wikipedia.org/wiki/Environ...dio_extensions

I'm not 100% sure, but I think the surround effect is not from the audio-enhancing portion but from the game engine (talking to the operating system) itself. The game is telling OpenAL/EAX what effect to give to which sound, not which speaker or how loud each sound is. You can play with the environmental settings in most sound card software.

When games and such tell the sound card which speaker to play a sound out of, it is not in a DD or DTS signal. This is why we've always had to use analogue cables where the signals are broken out separately because it's not in a signal format a receiver can read. How long will we have to wait for a TrueHD encoder for games?