I might bought defective refusrbished arc from sonos

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