No PCM sound via 4k HDMIs

[lambis24]

I just bought a new 4K TV (upgraded from 1080). When I connect my laptop to one of the HDMI 2.0 for 4K video, my receiver does not recognise any PCM signal coming from the PC.
DTS and Dolby passthrough signals from VLC get recognized normally.
The TV is LG OLED A1 and I have DeepColor turned off. When I turn on 4K deepcolor on the TV, the amp magically plays PCM but not the DTS, Dolby passthrough or exclusive WASAPI. (Exclusive WASAPI does not play in either case.)

Any troubling-shooting or help appreciated.
Thanks.

Onkyo tx nr636
LG OLED A1 77”

 

[andy1249]

Your receiver is not eARC compatible ( 2014 model ) so can only get dolby digital or 2 channel PCM over standard ARC from the TV.

Also LG does not do DTS in any way shape or form , no passthrough , no decoding , nothing.

So how exactly is your laptop connected to the receiver , Im assuming some kind of separate connection for audio as otherwise DTS would not be possible.

Any configuration whereby the LG TV is sent DTS will cause issues.

 

[lambis24]

Your receiver is not eARC compatible ( 2014 model ) so can only get dolby digital or 2 channel PCM over standard ARC from the TV.

Also LG does not do DTS in any way shape or form , no passthrough , no decoding , nothing.

So how exactly is your laptop connected to the receiver , Im assuming some kind of separate connection for audio as otherwise DTS would not be possible.

Any configuration whereby the LG TV is sent DTS will cause issues.

Many thanks for the reply, I am currently at work so I will test stuff later today (europe).

My laptop is connected directly to the Onkyo receiver via a 4K HDMI port. Then the receiver sends the signal to the TV via the main HDMI out. PCM audio works fine on any HDMI on the receiver which is not 4K ready (so i am assuming not HDMI 2.0).

The receiver can decodes the DTS and Dolby signals in that setup I pressume.

 

[dante01]

Your AV receiver should have no issue with handling PCM, eirgewr 2 channel or multichannel. If the PC is connected firectly to the AV receiver and if not passing the audio through the TV then you should be getting multichannel PCM if that is what the PC is outputting?

Ot has nothing to do with the video resolution. Both your TV and the AV receiver can handle 4K/60Hz video.

Yes, your AV receiver can also decode both DTS and Dolby Digital and can even decode TrueHD or DTS-HD MA. Just about any digital AVR will handle PCM.

I'd suggest you connect sources directly to the AV receiver as opposed to connecting them to your TV and then passing audio through that TV. Your AV receiver has more comprehensive audio decoding than your TV and support for more formats than that TV.

I'd double check that you've not configured the AV receiver to pass audio through and out to the TV. If you've configured it to do this then the source will used the EDID onboard the TV and the TV's audio handling capabilities to determine what audio it can output. SEt the AV receiver so it only passes video through and not audio.

The issue you are having may in fact be simply something to do with how you've configured the PC?

 

[lambis24]

Your AV receiver should have no issue with handling PCM, eirgewr 2 channel or multichannel. If the PC is connected firectly to the AV receiver and if not passing the audio through the TV then you should be getting multichannel PCM if that is what the PC is outputting?

Ot has nothing to do with the video resolution. Both your TV and the AV receiver can handle 4K/60Hz video.

Yes, your AV receiver can also decode both DTS and Dolby Digital and can even decode TrueHD or DTS-HD MA. Just about any digital AVR will handle PCM.

I'd suggest you connect sources directly to the AV receiver as opposed to connecting them to your TV and then passing audio through that TV. Your AV receiver has more comprehensive audio decoding than your TV and support for more formats than that TV.

I'd double check that you've not configured the AV receiver to pass audio through and out to the TV. If you've configured it to do this then the source will used the EDID onboard the TV and the TV's audio handling capabilities to determine what audio it can output. SEt the AV receiver so it only passes video through and not audio.

The issue you are having may in fact be simply something to do with how you've configured the PC?

I will double check all audio passthrough settings on my receiver when I get home.

The only reason I mention that the port is 4K, is that on a regular FHD HDMI port on the receiver everything works just fine as far as I tested yesterday.

 

[Mark.Yudkin]

Make sure that the Onkyo's "HDMI through" option is set to False, otherwise the TV will dictate what the sources may do, and the LG TV can't do various things (see andy1249's post #2), thereby crippling the system.

Also check that either you are not using the HDMI 3 input on the Onkyo (that's the HDCP 2.2 input) or that your laptop supports HDCP 2.2.

 

[dante01]

The source doesn't need to be HDCP 2/2 (or 2.3) compliant in order to be able to output video to an input that is. HDCP 2.2 protection is only applicable to commercial UHD video. Older devices and non HDCP 2.2 digital copyright compliant devices can still be connected to inputs that are HDCP 2.2 compliant. Lower resolution and content protected by HDCP 1.4 should still passthrough such an input.

Also note trhat if getting video then it hasn't anything to do with HDCP. HDCP is only applicable to video and not audio.

Issues with HDCP don't effect audio. If you were having issues with HDCP then you'd not be able to access either the audio or the video. It doesn't ever result in you losing the audio while still being able to access the video.

 

[lambis24]

Nothing worked. I believe the I've narrowed down the problem to the "HDMI Deep Color for UHD" on the LG TV.

When it is off, no PCM sound.
When it is on, only PCM stereo no DD or DTS.

The only thing that changes anything, and also explains why I have sound on non-4K HDMI ports.
But it is OFF goddammit!!!......

 

[dante01]

The Deep Colour setting on your TV shouldn't effect the audio.