Sonos has yet to announce whether or not their products will support Apple Lossless or Dolby Atmos audio from Apple Music. But the fact that Sonos currently supports 24-bit/48 kHz streaming on Qobuz and also supports Dolby Atmos music on Tidal through the Apple TV 4K is a good sign that Apple Music Lossless/Dolby Atmos support is definitely possible.

Thanks for the response and the positive vibes

Ok so has anyone tried this, I’m pretty sure you can get lossless music on ATV4K now (24bit / 48khz)

If atv4k is connected direct to my LG CX and then eARC out  (passthrough)  to the sonos arc will I get the better format.

Has anyone tried?

This is definitely working this morning.  Apple Music has playlists available with songs in Dolby Atmos ready to go, and the Sonos app is showing them in Atmos with the Arc 5.1 setup.

I also got Dobly Atmos Logo on Apple Tv 4k 2020 with Sonos Arc / 2 x Sub Gen. 3 / 2 x Sonos  SL. 
 

Will be there a difference if I change the One SL with 2 x Five? 
 

thank you,

Norbert

Can confirm Atmos from Apple Music App on Apple TV 4K to Arc. 
 

Haven’t been able to stream Atmos via AirPlay directly to the Arc on iPhone with Apple Music yet, anyone else had any luck?

AirPlay 2 doesn’t handle an Atmos signal. You have to use the TV to get an Atmos signal into the Sonos Arc, which means using an Apple TV to send the necessary signal to the TV, which then forwards it to the Sonos. 

That's my understanding too, if you want Atmos or Apple spatial music you have to use the Apple TV box, you can't stream it from your phone/tablet etc 

I just set up my Apple 4K tv.  Was a bit of a faff to get the settings correct but got there in the end.  (As usual YouTube videos came to the rescue to help with the set up.) 
 

I now do indeed have Dolby Atmos music playing on the Sonos arc.  This is indeed the only method as of today to get Atmos music on the arc. 
 

I have to say it was well worth the fiddling around as I have listened to some of the Atmos playlists available on the music app. It is a completely new experience.  I particularly enjoyed the  Jazz and classical music playlists.   The music simply fills the whole of the room and is totally immersive.  
 

Obviously it would really be so much easier if the Sonos app would pass Atmos music via the app without the need for the Apple TV.   Hopefully this will come in the not too distant future..