Apple TV 4K - either Atmos or 5.1 work but not both

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Jignesh Shah Author

Level 1

11 points

Apple TV 4K - either Atmos or 5.1 work but not both

I have the following:

Apple TV 4K connected to Samsung OLED QN65S90 via HDMI

Sonos Arc connected to the Samsung via HDMI on the eARC port

Here is what happens.

1) Atmos works if available. But 5.1 content comes through as Stereo PCM

Under Apple TV Settings > Video and Audio > Audio Format

Change Format = Off

Dolby Atmos = On

2) Everything from the Apple TV come through as 5.1 including Atmos content

Change Format = On

New Format = Dolby Digital 5.1

Dolby Atmos becomes Not Available

How do I get Apple TV to work correctly so that it sends Atmos or 5.1 content as available?

Apple TV 4K

Posted on Dec 14, 2023 3:58 AM

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Answer 1

Urquhart1244

Level 10

146,250 points

Dec 14, 2023 1:31 PM in response to Jignesh Shah

(1) For content with surround sound (e.g. 5.1), Apple TV in the Auto format setting is supposed to send out uncompressed PCM Multichannel — PCM, but not stereo. It wouldn’t send out as compressed Dolby Digital 5.1, regardless of source format: everything gets decoded to PCM. That is intentional. Don’t be alarmed by the 3-letter mention of ‘PCM’ per se, as decoding would be lossless.

If it really says ‘Stereo’ for you, then either your TV or Sonos is doing something unintentional with the signal, or else misreporting the actual format.

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