Are there really eight distinct audio channels?

haskellbob

Novice Member
Hello. I want to watch movies on my computer and hear the 7.1 surround sound.
Is this really possible? What I don't understand is how eight channels can go through RCA outputs/inputs. I'm guessing they can't.

If I use a Digital-to-Analog converter, again the same question.

I'm getting the sense that HDMI is the medium for getting all eight discrete channels sent from computer to receiver. I have a Sony STR-DN1080.

Problem: my computer does not have an HDMI slot. Also, its sound card does not accommodate 7.1 surround sound.

Does a DAC solve both problems for me? Can it take eight channels from a downloaded movie and send them to my receiver? What I don't get is why DAC's don't have HDMI slots. Do they convert eight channels into signals that can somehow be transmitted through two RCA cables? If that were so, to my way of thinking, they would have to have included in their information some kind of "multiplexing" that would allow the two channels to be separated back into eight. But I'm probably wrong. Still, why do people want to convert digital into analog in the first place? I just don't get it. Digital what? My brain is stalled.

And please help me understand the technology of transmitting eight channels from the computer to the receiver. I could understand if someone would just say, "All eight channels of sound pass through the HDMI cable." If that's the case, you can just quote me!

Will appreciate any help.
 

gibbsy

Moderator
I know nothing about computer audio, never had to bother with it. An analogue connection is restricted to stereo. HDMI can carry multiple audio in the form of bitstream to the Sony. It would be the Sony that converts the bitstream signal to analogue and thence to your speakers. You would need a sound card on the computer to facilitate multi channel audio as well as a HDMI connection to the Sony.
 

haskellbob

Novice Member
Thanks for your reply. So if I install a sound card with multi channel audio, as well as a graphics card with an HDMI output, the several channels of audio would be sent through the HDMI cable, I assume. Is that right?
 

gibbsy

Moderator
Yes.
 

haskellbob

Novice Member
Hi again. Thanks for your response.
My computer has a Displayport slot. If I hook up a Displayport-to-HDMI converter, would the sound be transmitted correctly?
 

I am Jon

Active Member
Hi again. Thanks for your response.
My computer has a Displayport slot. If I hook up a Displayport-to-HDMI converter, would the sound be transmitted correctly?
No need for a sound-card if using HDMI to connect audio from the computer, best to let your receiver act as the DAC. A Nvidia geforce 1030 or better with HDMI will defiantly work for 7.1 out. I use a geforce 1070 plugged into my old Denon AVR via HDMI for computer audio.

Which HDMI audio formats do NVIDIA GPUs support?

Display-port to HDMI adaptor should still work for surround sound but can't guarantee without testing it on your setup.
 

haskellbob

Novice Member
thanks for that. More questions: The Displayport slot isn't backed up by anything other than the hardware that came with the computer, so I don't know if that's capable of doing 7.1. Is it? It's an
HP Elite 8200 SFF Desktop PC - Intel Core i5-2400 3.1GHz 8GB 500GB. Also, the slots inside are just PCI, not PCI E. Is there a graphics card that I can put in there that will handle this, or am I looking at new computer time?

Thanks again.

 

I am Jon

Active Member
In your case the CPU "Intel Core i5-2400" includes a integrated GPU which powers the Display-port and VGA outputs. This isn't powerful enough for modern 3D games but is sufficient for normal web browsing and video playback.

Surround sound should be possible over display-port with an hdmi adaptor but on some older computers the displayport / hdmi connectors do not fully support digital audio. Best way to find out is try a $10 adaptor and see if it works. You don't need a dedicated sound card for outputting digital audio, a dedicated sound cards main job is to provide high quality analogue outputs.

Graphics cards normally use a PCIe x16 connector. PCIe connectors come in different sizes x1, x4, x8 & x16, x16 connectors support the higher bandwidth required by GPU's and are about 9cm long. Most motherboards have 1 to 2 long PCIe x16 connectors along with a couple of smaller PCIe x1 connectors. I expect your HP Elite 8200 has at least 1 PCIe x16, It may also have some PCIe x1 and older PCI connectors (see link below for illustration).
Introduction to PCI Express
 
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haskellbob

Novice Member
Thank you much for writing all of that. It helps me know what I'm doing. I've ordered a cheap displayport to HDMI and when I get it I'll try it out.

But I also ordered a graphics card that has an HDMI output. And as I understand it, that card will also handle 7.1 surround, somehow. At least it says that on the specs. It's a SAPPHIRE Radeon HD 5450 Graphics Card PCI-E 1GB DDR3 HDMI DVI VGA .

So that might kill two... birds? with one stone. It will upgrade my sound capabilities and facilitate transmission of 7.1 channels to the receiver. I do believe there is a PCI-E slot in the computer. Oh, and I'm not into games. Movies and music are more my style. The last video game I played was Pac-Man, when it was new.

Anyway, I'll find out soon whether I can ascend to surround sound or there are more steps to take.

Thanks again for the effort it took to explain those things. I appreciate it.
 

I am Jon

Active Member
Have you managed to get a display connected to your Sony STR-DN1080 yet?

Just seen Amazon have Fire TV Sticks discounted again $29.99. They really are a great way to get you started streaming surround sound movies from Netfix and Amazon Prime or music from Spotify and Tidal. So long as you have a display working with the receiver, wifi and a Netflix / Amazon Prime / Spotify / Tidal subscription.
 
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haskellbob

Novice Member
Would you believe that I haven't gotten that yet? On Friday I'll get a displayport-to-HDMI converter and hopefully that'll do it. And I'll try to get the Fire Stick too. I do have a subscription to Netflix, so... One step at a time. At least I got it hooked up for 7.1. surround, with the speakers all around me.

Thanks
 

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