Audio using HDMI from video card - Passthrough from Mobo/Soundcard?

[Actaeon]

I have what I think its a simple question, hoping I can get some clarification.

When using HDMI out from a video card for both audio and video output, does the video card take over for all of the sound encoding or does it pass through from the motherboard or sound card?

My motherboard has built in SPDIF but I need to use HDMI from the video card to pass sound to my TV. I am having some trouble getting anything but stereo sound so I hope by knowing what devices are responsible for audio it'll simplify my troubleshooting a bit.

Video card is a Nvidia GTX 980 Ti
Motherboard is an Asus Sabertooth P67 w/ Realtek ALC892

Thanks.

 

[vailr]

The GTX 980 Ti video card includes an on board audio chip, which is completely separate from any of the motherboard audio ports. For 5.1 audio functioning via HDMI on the TV, you would also need to double-check that the version of HDMI port on the TV is sufficiently up-to-date.
The GTX 980 Ti includes an HDMI 2.0 output port, and the TV's HDMI input port is probably an older version.
http://www.brighthub.com/computing/hardware/articles/27727.aspx
https://en.wikipedia.org/wiki/HDMI#Version_comparison

 

[dave_the_nerd]

The audio card is responsible - it's a second sound card, essentially.

And it's not really "decoding" anything - it's streaming a digital signal to the TV, which handles the decoding itself.

 

[JeffMD]

The default Windows setup for HDMI audio usually has the pc streaming all audio channels as pcm. If you aren't hearing anything in a movie check to make sure it isn't bitstreaming a format like dts that the tv doesn't understand.

 

[JackMDS]

Choose the Video card audio as Default.

Then log to Win Computer Management/Device Manager, find the Sound Controller entry, right click on the Onboard audio device and click disable.

If you lose any Audio, you can right click again and enable.

 

[Actaeon]

Thanks everyone. The TV's HDMI input is actually HDMI 2.0a with HDCP2.2 capable. Probably more up to date than the 980 which is only HDMI 2.0 (for now ). The problem I am having is I can only select 'Stereo' from the speaker/audio settings in Windows, I want to select surround sound.

For more details on my setup...

Current setup is = PC --HDMI--> TV --SPDIF--> Z5500 speakers

Within the TV's audio settings for HDMI Audio Format (Input) I can select PCM or Bitstream. I select PCM because I heard it is uncompressed and higher quality than Bitstream. HDMI should be able to handle PCM just fine.

For Audio Format (output) I can only select PCM or DTS Neo 2.5. Dolby Digital and DTS are options but greyed out. It is my understanding that SPDIF can't pass 5.1 via PCM and goes to Stereo, so I am not using PCM on output. DTS Neo 2.5 is some type of decoding to mimic surround sound with a stereo feed, but it isn't real 5.1 and seems better of the two options.

The speaker's receiver/display says it is using DTS Digital.

I switched between a number of options and this was the best I could come up with. Dunno what else to try with the current equipment.

 

[JeffMD]

Samsung TV? You can only output multi channel formats when it is the TV itself that generates it, either over the air, through one of its built in streaming services, or playing back a movie from a usb stick. The TV doesn not support passing along bit streams over hdmi.

 

[Actaeon]

Yes, a Samsung TV. I was told that the J-series 2015s (or previous models upgraded with the 2015 SEK3500U evolution kit) will pass through 5.1 audio from HDMI via SPDIF out. I guess I should look into it some more.