I think you’re looking for a device like this, along with and HDMI splitter/matrix. This isn’t ARC, and it doesn’t really need to be, since you’re taking the audio signal before it reaches your TV or projector. I suspect this is going to add an delay in the audio though.
I can’t imagine that Sonos is ever going to make the device you’re looking for, since it already exists in a more generic form, and because Sonos already has devices specifically designed for use with TVs and projectors, as you pointed out. The audio input on the Fives are buffered to better allow syncing with other Sonos speakers/rooms and will be out of sync with and video source. Amp/Arc/Beam/Ray have inputs design for TV and will play the audio immediately to sync with the video source. You may not mind the sync issue with the Five, but it’s not a supported function by Sonos.
Not sure how reliable that would be in regards to keeping in sync with video. The Arc/Beam/Ray’s buffering are already on the bleeding edge of the ability to discern lip sync issues, and most of the signal is from the L/C/R channels which do not have to be buffered and transmitted. It has been speculated this is the reason Sonos can’t allow separate L/R front speakers, and that problem would increase with separate L/C/R.
since you’re taking the audio signal before it reaches your TV or projector.
I guess I failed to mention that I’m using the built-in Android TV on the projector, not an external source. This isn’t really a home theater setup, this is a projector on my coffee table with a pull-down screen.
The sync issues makes sense.
