Sign in with
Sign up | Sign in
Your question
Closed

Realtek HD audio, Optical out. Games in 5.1?

Last response: in Components
Share
March 28, 2009 9:55:07 PM

Hey, all.

Recently I hooked up my computer to my HT system so I could stream such things as Netflix and Pandora, and of course do some gaming on the big screen. One thing I was expecting was being able to get 5.1 surround when gaming. I'm not

I suspect it's just the Realtek on board audio that isn't able to do this. Maybe somebody confirm or possibly shed some light on the mater.

Here's my setup and what I've tried so far. My complete computer specs are in my profile.

It's an Abit IP35-pro motherboard with a Realtek 7.1 HD audio.
The HD audio is enable in the BIOS.
I have the latest Realtek driver.
My OS is Vista Ultimate 64 bit.
The game I used was COD4 which has an option to send 5.1 audio.

For the Video I have a DVI to HDMI cable going from my 8800GT to my receiver and for the audio I have an optical cable going from the output on the back panel to the input on my receiver. Funny thing is when I play a DVD I get a 5.1 signal. I just tested it with War of the Worlds and my receiver, when set on "auto" was getting an actual DTS input and not PCM. Anyone who has watched this movie on a HT system with a decent sub knows what a good LFE signal can do to your room. :D  Anyway, I was surprised to see the DTS light up on the receiver. I really didn't think it would decode it.

So that's where I get lost.

Is is the hardware?

A. The sound card is not compatible with 5.1 audio and gaming.
B. It might do 5.1 gaming, but not through the optical output. Just the speaker outputs.

Or is it the software?
The game?
Realtek driver issue?
Vista issue?



I'd really like to get some help before I go and put down the cash on a decent sound card.

Thanks in advance.


March 29, 2009 4:48:08 PM

For those who would like to know the answer to my question I found a really good thread over at the http://www.avsforum.com/avs-vb/ forums.

http://www.avsforum.com/avs-vb/showthread.php?t=966518

The conclusion is if you want to get the 5.1 audio from the game to a receiver you will have to use the analog speaker outputs. It doesn't get sent through the optical cable. Of course to do this you will also need 5.1 analog inputs on your receiver.

Some soundcards today have DD and DTS live which will only simulate a 5.1 from a 2.0 signal through the optical output.

This info is exclusively for gaming. Most soundcards can decode and pass DD and DTS through the optical cable when playing a DVD on the PC.


I'm still going to poke around a bit. That thread is a little over a year old now. Probably wasting my time though.
March 29, 2009 5:21:49 PM

Slight correction:

Someone over at AVS responded to a post I made.
Apparently soundcards with DD live will send 5.1 audio from games through the optical output. it's not simulated. Even better if you have a card that does both DD Live and EAX 5.

The question now is does it work with Vista as Vista does not support hardware acceleration like EAX 5. Not sure about DD Live, yet.


Related resources
April 1, 2009 12:54:19 AM

Quote:
Tom's Hardware: Over 1.4 million members in 6 different countries available to answer all your high-tech questions. Sign up now! Its free!

I must be speaking the wrong language.
:pt1cable: 
April 1, 2009 11:59:40 AM

I'll explain it this way:

Optical output can only carry a few outputs:
Uncompressed 2.0 PCM (up to 192 KHz/Sec)
Dolby Digital 5.1
DTS 5.1

Both DD/DTS requires that your sound system is able to decode the incoming signal for the output to be sent to your speakers, hence why they are generally not used as output. Instead, 2.0 output is generally upscaled to 5.1 using other methods (DTS Neo PC, Dolby Pro Logic, etc).

To get 'true' 5.1, you either need a receiver/speakers than can decode an incoming DD/DTS signal, or connect using HDMI, which can carry 5.1/7.1 as uncompressed PCM, removing the need for a decoder. Alternativly, you can use the older analog connections to hook an individual speaker to an individual sound channel (still the best option for PC's, for the above reasons).

As for gaming, I know the Realtek chipet supports 7.1 audio on most newer boards. CoD will set your speaker setup to whatever setup Windows is set to use. Go to the sound settings tab on the control panel, and make sure the speaker setup is set to 5.1.
April 4, 2009 5:00:29 PM

Thanks for the reply, gamerk316.

I think I found my answer. Any soundcard with Dolby Live will do what I'm looking for. What Dolby Live does is convert PC audio in things like games into a Dolby signal that will pass 5.1 through the optical cable. It does not upscale or matrix it into a faux 5.1.

The best my on-board audio can do with games and the optical output is a 2.0 stereo output. My receiver has a number of Dolby Pro Logic and other Multi-channel technologies that will only matrix a 5.1 signal from that. Of course movies from DVDs are a different story. The Realtek audio can actually decode and send it as Dolby or DTS 5.1

As you mention with COD and Realtek there is a 5.1 option in both the game and the PC audio console. However this only gets sent to the analog speaker outputs.

In short, my options are buy a 25 foot analog 5.1 audio cable and then plug my computer speakers into the headphone output, or buy a soundcard that supports Dolby Live.

I think I just found a valid excuse to spend more money on my PC. :D 
August 8, 2009 8:29:17 AM

Found this from a google search, I just want to thank you for doing all the research for me.
October 5, 2009 3:21:21 PM

This is one of the main reasons I do not upgrade my PC. It is an old orginial Athlon (Barton) on a A7N8X-Deluxe. It supports exactly this! Only NVidia MoBos did this without the need for an expensive sound card. Soundstorm was the technology back then. It amazes me that on computers sound cards went for HD before this.

I would like to know how much time PCs spend playing BDs vs games etc.
October 5, 2009 4:48:49 PM

Well, most soundcards have an optical out and support DDL/DTS-C these days; I'd say that a reciever to decode the resulting signal is more expensive then the soundcard...

Yeah, Soundstorm was awesome back in the day...
Anonymous
January 16, 2010 1:31:47 PM

Well, problem is actually... your onboard sound card can't encode in DD. So you cannot encode the 5.1 from the game into 2 channels to pass through optical which then get decoded by your receiver. You won't get true surround unless you can get the proper 5.1 channels encoded.

I've come pretty close, I can encode and send the signal to the receiver by creating a virtual sound card which gets filtered by AC3filter which does the encoding and I can get it to output via the optical cable and get decoded by my receiver, but I just found out the virtual sound card can't actually pick up 5.1 channels from the game! It only picks up 2 channels which I can see through the filter.. so back to square one.

Looks like I'm going to have to buy a sound card. Any ideas anyone on a sound card that can encode/decode DD/DTS and output via optical? Cheaper would be better.
January 16, 2010 2:40:25 PM

I'm running a Diamond XtremeSound 7.1/24 bit Sound Card with Dolby Digital Live ( XS71DDL ) that I got at Amazon for like 50 bucks. It was the cheapest name-brand card I could find that will do Dolby Digital Live. Let Vista install it, I've heard. I didn't, and I had to get the C-Media driver to make it work. Another thing, it wants your Windows Sound set to "Speakers".

Crysis takes a slight frame-rate hit from the DDL, but I can live with it. Analog card-to-receiver is the right way to do this if you have the inputs, though. DDL also compresses.
January 24, 2010 10:28:08 AM

yes my old motherbord was a premium one asus it had dolby live.new motherboard is deluxe model.but dont hace dolby live.now i dont get 5+1 from coax with my newmother board.my old motherboard was great in games.with coax it gave 5+1.i never tought dolby live was a big geal.but i was.
Anonymous
March 30, 2010 3:38:13 PM

I've had great luck with the Turtle Beach sound cards. I got mine for about $25 and it works wonders; does everything I need it to for surround sound in games, movies, everything really...
August 11, 2010 12:13:08 AM

Well, luckily I have 5.1 6 channel input in my Logitech Z5500 audio receiver, so this post saved me from the frustration of not being able to get 5.1 surround sound in games.

The analog output works fine and I am getting decent quality surround sound with my games.

This looks a reasonable solution till I figure out a way to fit a sound card in my machine (only one free PCI slot left after wifi & radeon 5870, which is covered by 5870).
August 11, 2010 4:16:50 AM

Amusingly enough, your 5870 has probably the best sound card in your system.
August 11, 2010 12:08:29 PM

Not really; it basically just includes a basic realtek chipset on the card iteself.

But yeah, to reliterate:

The only way to get 5.1 over optical/coaxial is to pass a Dolby Digital/DTS audio stream.

As games (typically) don't use either format, you need a soundcard with either Dolby Digital Live or DTS Connect to convert a 5.1 PCM audio signal to either Dolby Digital or DTS formats.
August 11, 2010 1:25:00 PM

astrallite said:
Amusingly enough, your 5870 has probably the best sound card in your system.


I'll elaborate a little on my efforts.

Realtek onboard optical (SPDIF) output:
I set this as a standard output. I tested Dolby/DTS audio in playback settings, worked fine. I played DVDs/files with surround sound, and my audio receiver successfully recognized Dolby/DTS.

But games couldn't. Games output was stereo.

Radeon 5870 HD output via HDMI:
Unfortunately my Logitech Z5500 doesn't have HDMI input. So, I connected my Bravia to desktop via HDMI. And my Bravia is already connected to Logitech Z5500 via optical. When I tested this setup with DVD/video files with surround sound, success.

I expected this to work for games, but it didn't. Games still output stereo.

Realtek onboard 6 channel direct output (three pin, one for sub, one for front speakers & one for rear speakers):
This is the only option where games worked fine for me. I could get surround sound from NFS.

Unfortunately this isn't a good option for music (mp3) playback and video playback as the Digital sound over optical/HDMI is way better.

Conclusion (for now):
I use Realtek onboard optical SPDIF output for normal stuff (music, movies)
I switch to Realtek onboard 6 channel direct output when I need surround sound in games

If you think I can improve upon this arrangement, I would be more than happy to try any possible suggestions. Any help would be really appreciated.
August 11, 2010 4:43:23 PM

Quote:

Realtek onboard optical (SPDIF) output:
I set this as a standard output. I tested Dolby/DTS audio in playback settings, worked fine. I played DVDs/files with surround sound, and my audio receiver successfully recognized Dolby/DTS.

But games couldn't. Games output was stereo.


Correct, and this is normal. Movies/DVD's are already encoded in Dolby Digital or DTS formats, which can be carried over SPDIF. Games however, use uncompressed audio, and an uncompressed 5.1 audio signal can NOT be carried over a SPDIF connection, so you get 2.0 instead.

The only way to solve this problem is to get a soundcard that can handle real-time encoding to either Dolby Digital or DTS. [A cheap option is the ASUS Xonar DX [Dolby Support only] or the HT Omega Striker, both going for about $80 or so]

Remember, SPDIF can ONLY carry:
2.0 Uncompressed PCM audio
5.1 Dolby Digital
5.1 DTS
6.1 Dolby Digital EX (??I'm not sure on this one??)

Quote:

Realtek onboard 6 channel direct output (three pin, one for sub, one for front speakers & one for rear speakers):
This is the only option where games worked fine for me. I could get surround sound from NFS.


Exactly, each connection carries two channels worth of uncompressed audio, and should work in all cases [provied the source has all the necessary channels, of course].

Quote:
Unfortunately this isn't a good option for music (mp3) playback and video playback as the Digital sound over optical/HDMI is way better.


Usually, the reverse is true. Analog does a MUCH better job of saving the highest and lowest frequencies of an audio track, which are lost in the process of digitizing the audio signal. But unless properly shielded, teh output signal won't be nearly as clear as a digital signal would be.
August 11, 2010 9:19:17 PM

This topic has been closed by Mousemonkey
!