Sonos will release a new app and operating system for its speakers in June - The Verge
Sonos Will Soon End Software Support for Its Older Speakers | WIRED
Sonos Arc 5.1.2 Home Theater Bundle (Black Arc, White Sub/Surrounds) Includes Sonos Arc Dolby Atmos® sound bar, Gen-3 Sub, and two Sonos One SLs at Crutchfield
Sonos won't update its oldest speakers anymore | WIRED UK
The Complete Sonos Buying Guide: Every Speaker, Soundbar and Amp Explained