Namely, the Play:3, Play:1, and second-generation Play:5 speakers, which had worked as surround speakers for all of Sonos’ previous soundbars, won’t perform the same trick for the new Arc Ultra.

The Arc Ultra is the first Sonos soundbar that doesn’t work with the Sonos Play:1 or Play:5 speakers – but it still works with Sonos One, Sonos Five, the Era models, or with two wired speakers ...