Analog 5.1 Receiver to PC

[DiscipleofWar]

I have a pretty straightforward question - I have an older Yamaha RX-V870 5.1 receiver / speaker setup, and I want to plug this into my PC and take advantage of the 5.1 surround.
There seems to be very little info on how to connect an analog 5.1 setup to a PC (clearly because this is now very old).
I just need to know how to correctly connect the receiver and the PC so the computer can play 5.1 sound. My mobo is newer and has all the standard analog audio ports.
Do I need to run separate connections from the front/rear/center out ports on the receiver to the different ports on the PC mobo?

See the following images for what I have to work with. I've been running audio from the "CD" RCA ports and that works for stereo, but not 5.1.

I'm assuming Low Pass is for the sub...

 

[djoye]

I looked at the manual and it looks like this unit only accepts stereo input and then uses Dolby ProLogic to make it 5-channel surround; the low-pass is definitely where you'd connect a subwoofer.

If your computer's sound device can send a ProLogic signal through a stereo jack then it might work using one 3.5mm -> stereo RCA cable into your receiver. If you have Realtek onboard audio, dig around in the audio software and see if there's an option for Dolby ProLogic. If so, enable that and set your receiver to Dolby ProLogic and you might get surround that way.

So basically, I'd plug the 3.5mm end into the front speaker plug on the motherboard and plug the red/white RCA end into whatever input you want on the receiver. Set Realtek to ProLogic, set the receiver to ProLogic and run a movie or game to see how it sounds.

Only problem I can think of is that most media will adjust itself based on how your speakers are set in Windows. If Windows is set to stereo speakers then most games will only output stereo; you might have to set Windows to 5 speakers.

This will require some some playing with since it's not just a straight-forward three stereo analog connections, HDMI, or optical to the receiver.

 

[NoxTek]

If your computer's sound device can send a ProLogic signal through a stereo jack then it might work using one 3.5mm -> stereo RCA cable into your receiver. If you have Realtek onboard audio, dig around in the audio software and see if there's an option for Dolby ProLogic. If so, enable that and set your receiver to Dolby ProLogic and you might get surround that way.

I don't think I've ever seen an audio solution (either onboard or dedicated) that can encode and output Dolby ProLogic. That would be pretty interesting if it were possible.

Luckily my 'ancient' late 90's Harmon Kardon AVR5 has discrete line level inputs for 5.1 audio.


Now for movies and video there ARE certain players that can downmix a 5.1 or 7.1 source and output a Dolby ProLogic 2-channel stream... but for general Windows usage and games I think the OP is SOL. I'm surprised someone hasn't coded a 'wrapper' of sorts for Windows to output ProLogic.

 

[djoye]

Now for movies and video there ARE certain players that can downmix a 5.1 or 7.1 source and output a Dolby ProLogic 2-channel stream... but for general Windows usage and games I think the OP is SOL. I'm surprised someone hasn't coded a 'wrapper' of sorts for Windows to output ProLogic.

I think PowerDVD will render ProLogic and I may have seen one or two games (I want to say GTA4 but that's probably wrong) that had ProLogic as an option; that might've been in some older Playstation 2 games, though.

I think if the Realtek chipset advertises or supports Dolby Home Theater that in the software it has a Dolby tab and you can select something like ProLogic IIx but that's all I saw from a Google search.

 

[DiscipleofWar]

Thanks for the feedback, guys.
Haven't quite arrived at a solution yet...with Windows set to 5.1, Realtek set to 5.1, and the receiver set to Dolby Pro Logic, I get some sound coming out of all 6 speakers, but no directional audio in games or blu-rays. It's like the receiver is just echoing/simulating the audio through the rear speakers.

One interesting thing - when I identify the audio input (on the PC) as "headphones", the center speaker seems to activate.

Bottom line, I can get the receiver to play audio through all 6 speakers, but Windows does not recognize 5.1 channels to play out of. In the Realtek control panel the test tones do not play anything out of the 2 rear speakers (and the center only when "headphones" is selected).

 

[djoye]

What model motherboard do you have?

 

[DiscipleofWar]

It's a Gigabyte 890FXA-UD5, purchased a couple of years ago.

 

[djoye]

According to the manual, that audio software for that motherboard has a Dolby ProLogic option but I'm thinking it only up-mixes audio when you have a discrete 5.1/7.1 system connected.

I think you're out of luck as far as getting any kind of multi-channel audio from your PC to that particular receiver. If you had a receiver with SPDIF input or direct 6- or 8-channel inputs on it then you could go that way but that receiver only accepts 2-channel analog signals so you're out of luck.

 

[NoxTek]

The Dolby Pro Logic IIx refered to in the manual for the above motherboard refers to the software's ability to take a 2-channel stereo source and matrix it to 5.1/7.1 audio, not the ability to actually dynamically ENCODE a Dolby Pro Logic stream into a 2-channel output.

Again I know of no consumer audio card that can take surround audio and encode it into a 2-channel output using Dolby Pro Logic / PLII (so that a Pro Logic capable decoder aka receiver can then decode it again). I'd absolutely love to be proven wrong... not necessarily because I actually NEED this functionality but because I'm into semi-retro audio and have more than a few mid 1990's receivers that do Dolby PL.

Realistically it's all analogue and so no one really cares about it anymore in the day and age where everything is digital and sent over HDMI or SPDIF. But a few of us still do.

 

[SirMaster]

Honestly you should just get a receiver with multi-channel input capability. I'm sure you can find an older used one on craigslist for ~$50.

 

[NoxTek]

Honestly you should just get a receiver with multi-channel input capability. I'm sure you can find an older used one on craigslist for ~$50.

Yeah... they definitely exist. My Harmon Kardon AVR5 (circa 1998 - 2000) is like my favorite receiver right now and it has them.

The thing is just built so solid and sounds fantastic.