No, it is not. At least not directly.  If you could send a local file with Dolby Atmos content to the TV, I imagine it would play in Atmos on the Sonos device connected to the TV. 

Hmm i see. I was hopeful that if play a local music to my era 300 wirh the right format, it d play.  @jgatie do you know what’s the format for dd enabled music ?

Sonos doesn’t play DD audio from local files.  Here’s a list of supported formats:

https://support.sonos.com/en-us/article/supported-audio-formats-for-sonos-music-library

Thank you very much!

Contrary to what people are saying and what the link previously provided would suggest, I have local Dolby Atmos music files stored in my media library that play perfectly through my ARC from the Sonos app. The only real flaws are that the songs/albums don’t get indexed properly in the app which is quite frustrating and now with the new app it doesn’t even show the file name when playing, it just says no title.

I remember reading about this a few months ago. What file type are the Atmos files? MP4?

@Allnew1234 interesting! Thanks for the info. As @GuitarSuperstar asks, what’s the extension? How big roughly the files ? 
lets’s all pray they will fix the new app soon!

Yes you can, contrary to the docs, you have to use DD+ JOC format:

This is interesting. I’m not sure but I think my files are different than what is suggested . The codec on mine are EAC3 and the extension is m4a. @arslanelver @GuitarSuperstar