No Dolby Atmos on Plex via Apple TV 4K 2021

Plex Players Streaming Devices
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Server Version#: 1.30.1.6562
Player Version#: 8.13

I have a Panasonic 4K HDR10+/Dolby Vision(& Dolby Atmos) TV with a full Home Cinema setup by Sonos.

I have plenty of my own movies in Plex that are TrueHD with Dolby Atmos.

However, when I play any content with Atmos from Plex on my Apple TV 4K 2021 model the correct Audio Codec information is not being passed to the Home Cinema system, with Sonos interpreting the sound as MultiChannel 7.1 PCM.

Everything else with Atmos across all streaming services and purchased movies works perfectly from the ATV 4K. Netflix, Disney+, ATV, Amazon Prime all correctly stream Atmos sound, with the Sonos App reporting the Dolby Atmos is being received.

Purchased movies in the Apple Store with Atmos also stream correctly, and are identified as Atmos.

So apart from Plex everything with Atmos sound streamed from the ATV 4K works correctly.

I thought I would run a test with an Nvidia Shield TV and Plex. I setup the shield correctly, made sure the correct audio codecs were being passed through and then run the same movies on Plex (Android) on Nvidia shield.

All movies tested previously on ATV 4K worked perfectly, and the Sonos app identified the streams were streaming Dolby Atmos.

So all fingers point to Plex on the ATV4K 2021.

Are others experiencing the same issues?

Is this an identified bug please Plex?? If so when will this be fixed?

Look forward to your reply?

Gary

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Apple blocks TrueHD passthrough on the Apple TV. It is converted to multi-channel PCM. Atmos information is lost in the process.

The streaming services use Dolby Digital Plus + Atmos, not TrueHD + Atmos.

The Nvidia Shield supports passthrough for TrueHD + Atmos.

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The identified bug is a well known fact that no versions of Apple TV 4K supports bit streaming of any audio formats. It always decodes them. With Atmos over DD+, that’s what streaming services use, it will be decoded into Dolby MAT that preserves Atmos. But Atmos over TrueHD is not supported and Atmos data will be dropped. You bought a wrong device for this.

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Thanks for your swift replies. Very disappointing.

I have re-installed my old Shield TV for now, which passes through the correct audio information.

I was about to buy a Gen 3 ATV 4K, but now, I think I will buy the latest Nvidia Shield TV which supports Dolby Vision and Atmos.

Thanks again chaps, really appreciated.

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Be sure to get the Pro model.

The non-pro “tube” model has problems with high bit rate media such as 4K HDR rips. There are several threads in the forum where people returned the tube model.

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I just bought the new AppleTV 4K Ethernet version. By what I am reading in this post it seems like I will have to send it back…

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