The Sonos One is the cheapest AirPlay 2 speaker you can buy

Almost a year after it was first announced, Apple has finally released its updated AirPlay 2 multiroom audio streaming platform. The company has also posted a list of devices that users can expect to work with AirPlay 2, including speakers from Sonos, Bang & Olufsen, and Libratone as well as AV receivers from Marantz and Denon (spotted by MacRumors).

None of the third-party speakers actually have AirPlay 2 yet; only Apple's own HomePod does right now. This is just Apple's list of the initial devices that will eventually support AirPlay 2 once these companies release their firmware updates, which don't really have any announced timetables yet.