Can optical audio cable do 5.1 for games?

UltraMega · Jan 17, 2019

I have a creative Sound Blaster RX. I am really confused about how to get 5.1 audio working properly with it.

I have my computer hooked up to a stereo amp via an optical cable. My Stereo is a Pioneer VSX-815. Recently I became aware of the weirdness about DLL and DTS Dolby encoding to get 5.1 over optical, but I don't really understand it.

Is real time 5.1 for games possible with an optical audio cable? Windows only lets me choose 2-channel output when I go to my sound card properties, however 5.1 channel movie files seem to work normally.

If there is no easy way to do this, then my next question is: does HDMI do 5.1 without the need for any dolby crap? If I got an HDMI reciver would I be able to use my sound card to do 5.1 from my PC at all times and not just for pre-encoded Dolby files?

Tiihokatti · Jan 17, 2019

Bandwidth of optical cable is small, so small that it only supports stereo signal without compressing/encoding. And that is where DTS/DDL step in, they compress the 5.1 (6-channel) audio signal to a tinier package so it can fit into the small bandwidth of the optical cable.
Movies already have pre-encoded DTS audio track, but games don't. This means that to use 5.1 in games you need a soundcard with on-the-fly DTS/DDL encoding support. Sound Blaster Z is among the cheapest options for that kind of soundcards.

As for HDMI, it directly supports all the forms of surround audio without the need for separate licenses (DTS/DDL). HDMI bandwidth is large enough so there is no need for encoding/compression.

UltraMega · Jan 17, 2019

Tiihokatti said:
Bandwidth of optical cable is small, so small that it only supports stereo signal without compressing/encoding. And that is where DTS/DDL step in, they compress the 5.1 (6-channel) audio signal to a tinier package so it can fit into the small bandwidth of the optical cable.
Movies already have DTS-encoded audio track, but games don't. This means that to use 5.1 in games you need a soundcard with on-the-fly DTS/DDL encoding support. Sound Blaster Z is among the cheapest options for that kind of soundcards.

As for HDMI, it directly supports all the forms of surround audio without the need for separate licenses (DTS/DDL). HDMI bandwidth is large enough so there is no need for encoding/compression.

So would it be better to get the sound blaster Z and used my optical cable or keep my sound blaster RX and get an HDMI receiver for the best 5.1 audio in windows? Is on the fly DTS/DDL over optical as good as HDMI?

As far as HDMI receivers go, so long as it's HDMI is the sounds quality going to be the same with one model vs another? Do I need to get a high end receiver to get the best audio quality over HDMI?

shilka · Jan 17, 2019

No you cant get 5,1 with an optical audio cable i have spent hours trying to it to work and it cant
You will need an HDMI cable if you want 5,1 audio

UltraMega · Jan 17, 2019

shilka said:
No you cant get 5,1 with an optical audio cable i have spent hours trying to it to work and it cant
You will need an HDMI cable if you want 5,1 audio

Apparently you can if you have a sound card that does live DDL/DTS encoding, which mine does not. My question now is if its better to do that or just get an HDMI receiver.

shilka · Jan 17, 2019

The only reason why i dont use an HDMI cable and still use the optical audio cable is i find that using the HDMI is extremely annoying
I listen to music pretty much all the time and with HDMI every time i turn the TV off or on it cuts the sound to the music for a few seconds

And then there is the anyoing overlay the receiver has which pops up and blocks the subtitles of whatever i am watching which is also extremely annoying
Would rather just have 2,1 in that case

Tiihokatti · Jan 17, 2019

UltraMega said:
Apparently you can if you have a sound card that does live DDL/DTS encoding, which mine does not. My question now is if its better to do that or just get an HDMI receiver.

Honestly I would just go with a HDMI receiver.
HDMI supports lossless 7.1/Dolby Atmos/etc. while DDL/DTS via optical only supports lossy 5.1.

Of course if you are on a budget then the soundcard with DTS/DDL is the only option.

UltraMega · Jan 18, 2019

Tiihokatti said:
Honestly I would just go with a HDMI receiver.
HDMI supports lossless 7.1/Dolby Atmos/etc. while DDL/DTS via optical only supports lossy 5.1.

Of course if you are on a budget then the soundcard with DTS/DDL is the only option.

I bought an HDMI stereo today for $80 on craigslist. Gonna set it up tomorrow when the HDMI cable I ordered on amazon arrives. Thanks for the help. Looking forward to full digital surround in games.

UltraMega · Jan 18, 2019

So now I'm feeling a little dumb. I didn't think about the fact that the receiver needs to be a 4K capable receiver in order for this to all work with the TV I have. I already went and got a Pioneer Receiver VSX-820 but it's looking like it will be pretty useless for me.

Is there any work around for this? Anyway to use an HDMI receiver that doesn't have 4k support to do 5.1 surround and still use my 4K tv from my computer?

Tiihokatti · Jan 18, 2019

You can set the receiver as a separate dummy monitor.
Try this:

https://www.reddit.com/r/htpc/comments/6gho50/windows_10_now_lets_you_mirror_a_4k_and_1080p/
TL;DR: Hook up both the TV and the receiver directly with your GPU. Then mirror the 4K screen to the "1080p receiver".

PS. If you are running a GTX 1070/1080 with only 1 HDMI port, you can simply get a passive DVI-to-HDMI adapter to get a 2nd HDMI port. The new port will work like a native HDMI 2.0 port. Been doing exactly that with Lenovo Explorer VR-headset as GTX 1080 only has one HDMI port (and Explorer requires HDMI 2.0).

UltraMega · Jan 23, 2019

So I'm just updating this for anyone else that goes down this path.

I did get full 5.1 surround over HDMI HDCP 2.2 and I hated it. It sounds bad, very digital, sharp, too much treble. Sound quality is a far cry away from what I had running optical out of my sound card or just using analog. I've come to find that analog really is the best option if your goal is to have the best audio quality. Still waiting on one more cable to come in the mail, and then I will be running full 5.1 surround over analog.

Save yourself all the experimentation that I went through and just understand that the only good thing about digital audio is convenience, not quality. Analog is king and that won't change anytime soon.

infranoia · Jan 23, 2019

I had a Soundblaster Recon3D PCIe with DDL going through optical to a B&K 5.1 pre-amp, and I thought it sounded great. But then I finally upgraded to a 4K HDMI receiver, an Emotiva MC-700, and the sound quality was night-and-day. Seriously, the HDMI + Emotiva was so much better than old-school optical that I didn't know what I was missing.

To be fair, the MC-700 is a processor / pre-amp not a receiver, but I changed out the amps from separate Marantz monos to the Emotiva A-700 so it was at best a side-grade there. I'm certain the audio improvements were almost entirely due to the increased bandwidth and better processing.

UltraMega · Jan 25, 2019

infranoia said:
I had a Soundblaster Recon3D PCIe with DDL going through optical to a B&K 5.1 pre-amp, and I thought it sounded great. But then I finally upgraded to a 4K HDMI receiver, an Emotiva MC-700, and the sound quality was night-and-day. Seriously, the HDMI + Emotiva was so much better than old-school optical that I didn't know what I was missing.

To be fair, the MC-700 is a processor / pre-amp not a receiver, but I changed out the amps from separate Marantz monos to the Emotiva A-700 so it was at best a side-grade there. I'm certain the audio improvements were almost entirely due to the increased bandwidth and better processing.

To each their own I guess. For me I think my older analog amp is actually much higher quality than the hdcp 2.2 amp I bought. Optical is digital though so you went from Digital to Digital with more bandwidth so it should sound better. Still, analog is superior to both when properly setup.

infranoia · Jan 26, 2019

UltraMega said:
Still, analog is superior to both when properly setup.

That's not an absolute statement and can't always be true. Analog from PC is always going to be subject to what soundcard you're using with whatever DAC it implements, how isolated your soundcard is, signal-to-noise ratio and whatever audio boosting and filtering algorithms it layers onto the analog signal. There is a lot of noise on a motherboard and PC DACs are really variable at their ability to filter it out.

On the other hand, digital is digital and the variability is then pushed out to your receiver stack, which also has DAC considerations, but I'd almost always trust a higher-cost receiver stack to do the DA conversion over an onboard or add-in PC soundcard.

TL;DR -- you can't really make absolute statements, everyone's audio system and PC is different.

Doubletap1911 · Jan 27, 2019

UltraMega said:
So I'm just updating this for anyone else that goes down this path.

I did get full 5.1 surround over HDMI HDCP 2.2 and I hated it. It sounds bad, very digital, sharp, too much treble. Sound quality is a far cry away from what I had running optical out of my sound card or just using analog. I've come to find that analog really is the best option if your goal is to have the best audio quality. Still waiting on one more cable to come in the mail, and then I will be running full 5.1 surround over analog.

Save yourself all the experimentation that I went through and just understand that the only good thing about digital audio is convenience, not quality. Analog is king and that won't change anytime soon.

I have a 7.1 system over HDMI and it sounds fantastic.

There are several ways to do surround sound on the PC and all of them have drawbacks but to me, it's worth it.

For those still wondering about surround over optical - while it is possible, very few sound cards these days have a DDL/DTSC encoder and the ones I tried a few years ago added an unacceptable amount of latency. Movies sound OK because they are already encoded, but having to encode and compress 6 channels of gaming audio in real time adds so much delay that it ruins the experience for me. If you're latency sensitive, there is a good chance you won't care for it.

Using analog inputs on a receiver (if you have an older unit or a modern high end unit with this feature) is probably the easiest way to go, but most receivers go into "direct" mode meaning you lost most of your receivers features and it tends to just act like a dumb amplifier. If your sound card does not have bass management, you'll find that your music only plays through the L/R channels and does not use the subwoofer (looking at you ASUS).

UltraMega · Jan 28, 2019

Doubletap1911 said:
I have a 7.1 system over HDMI and it sounds fantastic.

There are several ways to do surround sound on the PC and all of them have drawbacks but to me, it's worth it.

For those still wondering about surround over optical - while it is possible, very few sound cards these days have a DDL/DTSC encoder and the ones I tried a few years ago added an unacceptable amount of latency. Movies sound OK because they are already encoded, but having to encode and compress 6 channels of gaming audio in real time adds so much delay that it ruins the experience for me. If you're latency sensitive, there is a good chance you won't care for it.

Using analog inputs on a receiver (if you have an older unit or a modern high end unit with this feature) is probably the easiest way to go, but most receivers go into "direct" mode meaning you lost most of your receivers features and it tends to just act like a dumb amplifier. If your sound card does not have bass management, you'll find that your music only plays through the L/R channels and does not use the subwoofer (looking at you ASUS).

This is the issue I have now. I set it up with analog to my receiver but I don't get any bass at all. I bought a new sound card (sound blaster z) and I'm hoping that will fix it. The sound card I have now seems not to have any bass management. Do you know if this amp has any setting to allow it to get bass? My dad gave me this amp a long time ago so I don't know much about it but it seems to be a pretty good model. Pioneer VSX-81

Update: I'm not exactly sure what I did but it seems to now be working fully, with 5.1 surround over optical and without me needing to replace my sound card. I changed the listening mode around on my receiver and one of them worked right so I set it back to what I thought it had been set to initially and tested it again and now it's working. I'm a little confused by glad it's working.

infranoia · Jan 29, 2019

Glad it's working! I hope you enjoy your surround. FWIW Witcher 3 is great in 5.1, especially in a rainstorm.

Then there's always this: https://satsun.org/audio/

Doubletap1911 · Jan 31, 2019

UltraMega said:
This is the issue I have now. I set it up with analog to my receiver but I don't get any bass at all. I bought a new sound card (sound blaster z) and I'm hoping that will fix it. The sound card I have now seems not to have any bass management. Do you know if this amp has any setting to allow it to get bass? My dad gave me this amp a long time ago so I don't know much about it but it seems to be a pretty good model. Pioneer VSX-81

Update: I'm not exactly sure what I did but it seems to now be working fully, with 5.1 surround over optical and without me needing to replace my sound card. I changed the listening mode around on my receiver and one of them worked right so I set it back to what I thought it had been set to initially and tested it again and now it's working. I'm a little confused by glad it's working.

Either your card is using a surround encoder or your receiver is set to something that upmixes stereo into multi channel.

It is possible to cure the lack of bass management in a direct to receiver setup, but it requires some work in REW (Room Equalization Wizard). You basically take the sub bass frequencies from the other channels and copy them to the sub channel. More work than most people are willing to do and it's really a massive feature hole in sound cards that are missing this.

Can optical audio cable do 5.1 for games?

UltraMega

Tiihokatti

UltraMega

shilka

UltraMega

shilka

Tiihokatti

UltraMega

UltraMega

Tiihokatti

UltraMega

infranoia

UltraMega

infranoia

Doubletap1911

UltraMega

infranoia

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