LG OLED C9: PC audio via ARC (not eARC) Stereo Only?

VincentHanna · 24 Nov 2019 at 18:31

Thinking on solutions to this.

Could I not install a cheap Nvidia GPU and use the HDMI on that for audio?

hornetstinger · 24 Nov 2019 at 21:45

Pretty sure my LG c9 has raw and pcm setting on digital out

VincentHanna · 24 Nov 2019 at 23:56

hornetstinger said:
Pretty sure my LG c9 has raw and pcm setting on digital out

Ah brilliant

I set my TV audio to 'Auto' and turned on eARC (not that my avr supports it) and now my AVR says DD+

And it seems to be in 5.1 again.

That's better than stereo at least.

Chris [BEANS] · 25 Nov 2019 at 10:27

This thread is a goldmine!!

I have the same AV, and am very close to getting the B9, was wondering about this very issue, and it's all documented here!

Just to make suer I understand correctly... If I plug the GPU directly into the TV (obviously) then VRR will work fine, ARC the TV into the AV (obviously), and set the TV audio to auto, while setting the AV to TV, this should deliver Dolby Digital + in 5.1... right??

MassiveJim · 25 Nov 2019 at 11:01

VincentHanna said:
Ah brilliant

I set my TV audio to 'Auto' and turned on eARC (not that my avr supports it) and now my AVR says DD+

And it seems to be in 5.1 again.

That's better than stereo at least.

I played around for a couple of hours last night and could not get 5.1 on my PC

Chris [BEANS] said:
This thread is a goldmine!!

I have the same AV, and am very close to getting the B9, was wondering about this very issue, and it's all documented here!

Just to make suer I understand correctly... If I plug the GPU directly into the TV (obviously) then VRR will work fine, ARC the TV into the AV (obviously), and set the TV audio to auto, while setting the AV to TV, this should deliver Dolby Digital + in 5.1... right??

As above I haven't got it working as of yet, very frustrating I thought going from a 10YO Set to a cutting edge set would mean none of this kind of rubbish but it seems not

VincentHanna · 25 Nov 2019 at 11:04

What AVR do you have @MassiveJim

I should mention that I still had to set my Windows 10 to 'Dolby Atmos' (I already had the app) and that's when the receiver picked it up and showed the 'Dolby Digital' logo and then also D+

Either setting the TV HDMI sound to auto or enabling eARC seemed to make the bitstream work better.

MassiveJim · 25 Nov 2019 at 13:06

VincentHanna said:
What AVR do you have @MassiveJim

I should mention that I still had to set my Windows 10 to 'Dolby Atmos' (I already had the app) and that's when the receiver picked it up and showed the 'Dolby Digital' logo and then also D+

Either setting the TV HDMI sound to auto or enabling eARC seemed to make the bitstream work better.

Its a little older Marantz NR1504

previously I had everything connected to the amp and a single HDMI from AMP to TV (I think I was using ARC for normall TV)

however with this amp being a little older it doesn't support 4k, so now I have to plug anything that supports 4k into the TV directly.
There are ways around it (optical or 3.5mm to phone cables) but I was hoping to simplify everything with single cables.

FWIW I also tried the dolby atmos option but got no sound.

Does such a thing exist that would split the sound from HDMI and send it down a separate HDMI cable, I have found loads that will split it via SPDIF but I read that has other issues with lip sync etc.

hornetstinger · 25 Nov 2019 at 13:20

Damnit optical out is blocked even with a 90 degree adaptor. So for dvd and Android box can't route audio out of tv

MassiveJim · 25 Nov 2019 at 14:07

hornetstinger said:
Damnit optical out is blocked even with a 90 degree adaptor. So for dvd and Android box can't route audio out of tv

Can't you use ARC ?

hornetstinger · 25 Nov 2019 at 14:29

My av pre has no hdmi features

jpaul · 25 Nov 2019 at 15:12

MassiveJim said:
Does such a thing exist that would split the sound from HDMI and send it down a separate HDMI cable

I thought this was the solution ...

jpaul said:
Have not done this in practise but my understanding - you can get a £25 4k splitter/stripper that will send required 4K/10bit EDID&handskake to the shield (or other hdcp2.2 10bit/4K source), and splitter strips the hdcp at the output, so you can then send it to both tv(hdmi2.0/hdcp2.2) and AV amp(hdmi 1.4/hdcp2.0)
The AVamp will ignore the hdr metadata which is in the video stream;
of course, will need to ensure you send an audio stream from shield that works with av

james.miller · 9 Dec 2019 at 22:34

VincentHanna said:
Same as you.

I'm going to hazard a guess that Nvidia will only output the full range of audio options via HDMI.

I notice ASUS do a Strix 2080Ti with 2x HDMI ports - Obviously i'm not going to go to those sorts of lengths to get decent audio back, but maybe somebody who has one can confirm that both HDMI outputs offer the full range of audio options?

The solution appears to be a passive adaptor. More here:

https://www.avsforum.com/forum/26-h...o-receiver-through-dp-hdmi-adapter-cable.html

MassiveJim · 14 Dec 2019 at 11:15

So a little update on the 5.1 situation with a PC.

Thinking that 5.1 via ARC wasn't possible I built a new HTPC with an optical port.
However whilst tinkering and setting it up I managed to get 5.1 working via HDMI/ARC.

I use my machine almost exclusively as a KODI media player, the machine boots directly in to KODI without loading windows etc.
The solution was to set the sound to stereo within windows and Kodi, then in the settings in KODI there is a passthrough section, in there I turned everything on and set it to 5.1 and it works perfectly. The amp displays whatever version of Dolby the films were encoded with.
Haven't tried it in games yet as it was quite late last night when I made the discovery, but not that bothered if games don't work as main gaming rig is upstairs.

VincentHanna · 30 Dec 2019 at 10:21

james.miller said:
The solution appears to be a passive adaptor. More here:

https://www.avsforum.com/forum/26-h...o-receiver-through-dp-hdmi-adapter-cable.html

Did anyone ever try this?

jpaul · 30 Dec 2019 at 16:54

but like the link says,

AFAIK Nvidia cards allow you to have video going over one HDMI out and audio output to another HDMI connector (a D++ port with a passive adapter is considered essentially the same thing as an HDMI port), so it should be doable.

you need your D++ equipped graphics board first, which is tantamount to two hdmi's

VincentHanna · 1 Jan 2020 at 13:26

james.miller said:
The solution appears to be a passive adaptor. More here:

https://www.avsforum.com/forum/26-h...o-receiver-through-dp-hdmi-adapter-cable.html

UPDATE

It only flippin' worked!

Bought a basic 'Display port to HDMI' cable, plugged it in to the spare Display Port output and voila - All the multi-channel surround options:

And thanks to a certain generous rain-forest return policy, I can get back the the money I spent on a MSI NVIDIA GEFORCE GTX 1030 and my 2080Ti is back to 3.0x16 mode

james.miller · 1 Jan 2020 at 22:53

That's brilliant, glad it worked

Aidah · 12 Jan 2020 at 12:45

Signed up to say thanks for this. I'm about to pick up a C9 and was thinking about solutions to the exact issue. I guess DP to HDMI cable definitely works.

What I had originally planned to do was output video to the TV via the GPU HDMI out, and audio to the AVR via the motherboard's onboard HDMI out. Shouldn't that work as well?

Dan Beaman · 20 Feb 2020 at 10:05

VincentHanna said:
UPDATE

It only flippin' worked!

Bought a basic 'Display port to HDMI' cable, plugged it in to the spare Display Port output and voila - All the multi-channel surround options:

And thanks to a certain generous rain-forest return policy, I can get back the the money I spent on a MSI NVIDIA GEFORCE GTX 1030 and my 2080Ti is back to 3.0x16 mode

Just came across this problem.. so just to confirm do I have to keep 1 HDMI direct into the TV to allow VRR and then add 1 DP using a passive adaptor into the AVR to allow surround?
Thanks

VincentHanna · 20 Feb 2020 at 10:14

Correct. I've been using it for 6 weeks and it works great.

The minor downside is that the AVR is detected as another display/monitor (I 'Extend' my displays) so occasionally things will launch on that 'monitor' and I have to faff around slightly.