They all are. The One needs to be on S2 software though. See https://www.sonos.com/en-us/guides/sub3

If you are still on S1:

• Sub (Gen. 3) is compatible with the Sonos S2 app (for Android and iOS). Earlier Sub models are compatible with either S1 or S2.
• Sonos Sub is designed for use with most Sonos speakers, except Sonos Roam, Roam SL, Connect, Port, and Move. Make sure you set up at least one speaker before adding Sub.
• See Setup when you’re ready to add a Sub to your Sonos system.

Sub 4 is S2 only too.

Thank you.  Much appreciated.
When I’d checked with Crutchfield they said I couldn’t use the Sonos Sub 4 with the Sonos One Gen 2.