I have set up a multiroom Sonos compatible setup by using the following,
- Hifiberry Amp
- Beocreate 4C Amp
- Rogue Amoeba Airfoil - https://rogueamoeba.com/airfoil/mac/
Basically this allows to setup a pair of Beovox RL 60.2 spekers and a subwoofer in Wireless 2.1 stereo. The RL's are using each a Beocreate set up for Left and Right channel respectively, the Beovox Cona Subwoofer is using a Hifiberry Amp [in mono setup].
The addition of Airfoil [by using a mac mini as a server] to control the whole system via Spotify on the Iphone and play multiroom audio mixing both Sonos and B&O Beovox speakers.
My assumption is that as the connectivity is Airplay based, quality is still as high as that provided by the input (Spotify Connect in this case).
Any thoughts or ideas on the setup?