New Sonos Operating System

Sonos will introduce a new app and operating system, called S2, in June. Among other things, S2 will provide support for HD music files. I thought this article did a good job explaining the different options if you have a combination of S1 and S2 components:

https://www.consumerreports.org/wireless-bluetooth-speakers/new-sonos-app-and-operating-system/