Please Help Finding Sound Card With 7.1 Channel Optical Output

muskyx1

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Apr 20, 2005
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Trying to find a sound card for a P6T LGA1366 motherboard that provides 7.1 channel optical output. The onboard optical output only provides stereo output when feeding an external A/V Receiver. Would appreciate some suggestions.
 

Slugbait

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Oct 9, 1999
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Your mobo should do 7.1 over the TOSLink. My x58 mobo does...although it has a different audio chip.

First thing to do is verify the program you're using is set to S/PDIF. Then verify the content is set to DTS-HD, which is usually found in the movie's Setup or Audio menu. Then set your external receiver to Auto, and it should detect the 7.1 audio stream.

By setting the receiver to Auto, it will also detect if the content is DTS or AC-3 (5.1) or DTS-ES (6.1)

Blu-ray on a PC is a bitch for most people, but you should eventually get it to work.
 

mfenn

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What is your source material?

S/PDIF only has enough bandwidth to output 2.1 channels of uncompressed PCM audio. To get 7.1 over S/PDIF, you need to have a compressed Dolby Digital or DTS track. If you have 3+ channel uncompressed PCM, Dolby TrueHD, or DTS-HD Master Audio, you will need HDMI because they're too high of a bitrate for S/PDIF.
 

muskyx1

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Apr 20, 2005
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Your mobo should do 7.1 over the TOSLink. My x58 mobo does...although it has a different audio chip.

My onboard chip is Realtek. I mostly use it for gaming, so those advanced options aren't available.


What is your source material?

S/PDIF only has enough bandwidth to output 2.1 channels of uncompressed PCM audio. To get 7.1 over S/PDIF, you need to have a compressed Dolby Digital or DTS track. If you have 3+ channel uncompressed PCM, Dolby TrueHD, or DTS-HD Master Audio, you will need HDMI because they're too high of a bitrate for S/PDIF.

The video card is the older GTX285 that lets you feed 2.1 audio through the HDMI.

It's too bad, looks like I'll be returning the Onkyo TX-NR616 receiver I got over the weekend.

Thank You both.
 

Slugbait

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Oct 9, 1999
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Yeah, I don't know of any specific game that does 7.1 audio. Many do 5.1 over S/PDIF now. Some games are 5.1, but must be connected via analog cables...for example, I spent a couple of hours trying to get HL2 surround audio to work with my V333ES over both COAX and TOSLink, but kept getting PCM. Ran into a dev from Valve a week later, and he said, "No, sorry, gotta use analog cables for 5.1 audio." Was bummed.

With that said, 7.1 is more of a selling point for Blu-ray, most mid-level amps have that feature now. And even then, most people are pretty happy with 5.1. But I would agree...take that amp back. $400 is a nice price for a THX-certified amp, but the cost of the speakers to make the amp sound good will probably clean out your wallet.
 

Anarchist420

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I'm unhappy that uncompressed 2 channel audio isnt popular anymore. Also, I had thought that if S/PDIF had the bandwidth for 2 channel uncompressed (PCM) 24b/192khz, then it would have the bandwidth for 16b/44.1khz 5.1 channel PCM. I guess Dolby digital was actually used for storage reasons rather than due to bandwidth limitations.
 

mfenn

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I'm unhappy that uncompressed 2 channel audio isnt popular anymore.

What do you mean by this? It is a supported format for pretty much all equipment I know of. A ton of sources come with studio-mastered stereo mixes as well.

IAlso, I had thought that if S/PDIF had the bandwidth for 2 channel uncompressed (PCM) 24b/192khz, then it would have the bandwidth for 16b/44.1khz 5.1 channel PCM. I guess Dolby digital was actually used for storage reasons rather than due to bandwidth limitations.

Anything over 20 bits per sample is a non-standard S/PDIF extension, and is not guaranteed to work. In addition, 48 KHz is the design point for S/PDIF, with anything higher also being a non-standard extension.
 
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muskyx1

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Apr 20, 2005
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Thanks everyone, I returned the Onkyo TX-NR616 and replaced it with another Onkyo. But this time it was an HT-RC370. It has 7.1 analog input and other features that are not on the TX-NR616.
 

mfenn

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Thanks everyone, I returned the Onkyo TX-NR616 and replaced it with another Onkyo. But this time it was an HT-RC370. It has 7.1 analog input and other features that are not on the TX-NR616.

:thumbsup: When in doubt, analog will get you there.