Want to get “Dolby Atmos” via Audio Soundbar

The Sonos is intended to connect to a TV only, no video passthrough. So connect as:

Apple TV 4K →[HDMI]→ TV →[HDMI eARC]→ soundbar

If your TV doesn’t have HDMI eARC, then you may will need a different way to bring the high bandwidth Atmos audio to the soundbar. One often recommended device is the HDfury Arcana, specifically developed for such setups:

Apple TV 4K →[HDMI]→ HDfury Arcana →[HDMI-video]→ TV

↘︎[HDMI-audio]→ soundbar

Regular HDMI ARC on a TV doesn’t have the bandwidth that Atmos MAT from Apple TV 4K requires.

it did for me with Sonos Beam (Gen 2)

though spend some time because I was under the impression the tv's hdmi eArc was the specially marked hdmi port on my LG tv, which turned out it was not, so switching to the correct one made it all better.

You’re welcome. It would be great if you can follow up with your new experience.

I had to do exactly this with my setup when I got the Sonos Beam, because my TV did not have eARC. Can confirm adding the Arcana allowed Atmos and it has been working fine ever since.