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Question

Arc Ultra + Apple TV 4K Sound Format: Dolby Multichannel PCM vs Dolby Digital 5.1?

  • February 16, 2026
  • 1 reply
  • 57 views

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Hi everyone,

 

I’ve been doing some sound tests with my Sonos Arc Ultra + Sub Mini + two Ones setup and noticed something interesting.

When I use the Netflix app directly on my Samsung Q95T TV, the Sonos app reports Dolby Multichannel PCM 5.1.

When I use Netflix on my Apple TV 4K (3rd gen), Sonos reports Dolby Digital 5.1 instead.

On the TV, HDMI audio is set to Auto (no passthrough option available), and HDMI eARC is enabled.

To my ears, the audio from the TV’s built-in Netflix app sounds more “powerful” compared to the Apple TV.

 

So I’m wondering:

Which format is technically better: Dolby Multichannel PCM 5.1 or Dolby Digital 5.1?

 

Is one higher quality than the other?

 

Are there any settings I should tweak on the TV or Apple TV to get the best possible audio?

1 reply

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  • Prodigy II
  • February 17, 2026

If you ask AI then Dolby Multichannel PCM 5.1 is the best, something with how the sound is packaged.

Have you updated SONOS, your TV and Apple TV?
You can download the latest firmware for your TV here :Opgraderingsfil (USB) Version 2700.6 1635.91 MB 23 jun. 2025 Alle OS Multisprogdisplay

Is your HDMI cable from Arc Ultra plugged into eArc on your TV?

Settings on ATV see link: Apple TV 4K Setup for the Best Home Theater Experience (2025)

 

On your TV, you should be able to select passthrough.
Under the sound menu on the TV, it should say Arc Ultra under audio output.