https://en.community.sonos.com/announcements-228985/amazon-music-hd-available-on-sonos-6830070

My understanding is that if you use the Amazon app and ‘cast’ to Sonos you’ll only get SD.  You have to use the Sonos app to get a cd-quality stream. 

I’m adding albums in the Amazon app, and the playing from the Sonos app. 

However, albums I know really, really well, sound a bit 2 dimensional. 

They don’t sound bright or any hint of harshness you sometimes get with MP3, but they just sound like they are sat between the speakers, no depth, no width to the soundstage. 

This is just a connect into an old Arcam Movie Solo Amp (using the dac in the amp), pair of old Mission 752 Freedom speakers and a Rel Strata sub. 

If I play back the same file in FLAC ripped from CD it just sounds more open, deeper, wider, much nicer. 

The Amazon Ultra HD file sounds the same as Spotify. 

Is it definitely playing back 16/44?

What does the Amazon Music app say? That will label it as SD, HD or Ultra HD. 

The only way to tell whether Sonos is receiving 16/44 is to monitor the network bandwidth. Note that ‘casting’ from the Amazon app would reduce the Sonos quality to SD.

I’m just adding them in the amazon app and then playing it from the Sonos app. 

I am adding HD and Ultra HD tracks, I understand that Ultra HD (crap name) will be converted to 16/44 for Sonos, which is fine, but I’m not sure it is even doing that. 

Playing the flac 16/44 from my ripped file sounds open and airy, the Spotify and Amazon versions, (3 different albums available) all sound flat and shut in. 

Diana Krall - Black Crow is one of the tracks I am using. 

Either Amazon is doing something to the file or it is streaming in MP3. 

Same question here.