It might be because you have the Arc in a close place, try to leave space for the speakers on the top and in the rears. Put the Arc in this case in the part above, at the same height as you TV, where I can see have space :)

ok I have moved the arc as you suggested - no difference 🥲

Try to run the trueplay again, and also, view in the app if the source is Dolby Atmos, if not obviously the sound wouldn't hear as Atmos :)

i did the trueplay again, both sonos app and the tv shows ATMOS. Still nothing has changed ;)

So I think you need to call the support to check this, and also try this folder with sounds in Atmos 9.1.6, so can be a little more real idk.

i did the trueplay again, both sonos app and the tv shows ATMOS. Still nothing has changed ;)

 

Does your Sonos ‘now playing’ screen (with the big TV icon) show Dolby Atmos is playing when you’re playing this test content? That is crucial in this discussion.

i did the trueplay again, both sonos app and the tv shows ATMOS. Still nothing has changed ;)

 

Does your Sonos ‘now playing’ screen (with the big TV icon) show Dolby Atmos is playing when you’re playing this test content? That is crucial in this discussion.

yes it does 

Edit - sorry, misread…!

Do you subscribe to Apple Music or Amazon Music? If so, search for Dolby Labs and play some of their speaker test albums which have test tones, and see if that demonstrates Atmos better/properly.

Also adjust the height setting in the Arc’s settings in the app to ensure it’s set to high enough. The bounce off the ceiling is important for Atmos.

no, spotify only. 

height settings is set to 8/10. and actually a difference is subtle and doesn’t affect atmos effect 

Did you check using the files in the folder someone linked to earlier?

Failing that, you should call Sonos and they should be able to determine if there’s anything wrong with the Arc. Officially refurbished Sonos speakers are usually checked for functionality.

I’m slightly confused by your statement here. You say difference is “subtle” but doesn’t affect atmos effect. Any adjustment to the height channels reflect only affects atmos content.

In addition, from your original picture, it looks like you may have a slanted wall/ceiling. If that is true, how sound from the height channels reflects of the ceiling can impact on the effectiveness of what you are hearing from your seating position.

I could be totally wrong here but I'm not sure Sonos does a 1:1 mapping of each discrete channel (like how the sound engineer intended) and (re)mixes the sound to how they think it should sound(!) and have, in the past, said not to use such test files as they won't necessarily sound how they should. i.e. sound intended and mixed for a certain channel may come out of different ones on a Sonos Atmos setup because they know better.

First, double-check that your Xbox is set to “Bitstream out” with “Dolby Atmos for Home Theater” enabled. Also, make sure you’re using an eARC-enabled HDMI port on your TV, and that your TV actually supports Dolby Atmos passthrough. Sometimes the issue isn't with the Arc itself, but with how the signal is being sent. It’s also worth testing with actual Atmos content from apps like Disney+ or Netflix instead of just the Dolby app.