Sonos doesn’t really make any device intended to connect to a projector, but they do have inputs for an ARC or eARC connection on the Beam, and you could use the adapter to take an optical signal to the Beam’s Arc’s input. 

Maybe if you were to share what kind of audio output your projector does have, and perhaps a make and model number, this community might have more concrete suggestions. 

Thanks for your response. My projector has a 3.5 mm audio output. Can I use an adaptor to convert 3.5 to optical which can be connected to beam’s arc input. Please refer to the image below 

Projector make and model - Optima HD 28 HDR

3.5mm output only ever be stereo, never anything higher. 
 

Based on what I see on Amazon for this device, you’d be better off pulling the audio off the HDMI stream before the video reaches the projector, which will help some, as projectors warp t to be behind you, speakers want to be in front of you where the screen is.

I’d probably not worry about Atmos and all the associated angst around that, and go with a simple HDMI switch that has an optical audio out port. You’d then connect the Beam’s optical adapter to that audio out, and get the signal into the Beam’s ARC via that. 

You’re still going to need a bunch of long cables, both HDMI and optical, since the locations of the projector and the speakers are so different. But there are quite a few threads in the Home Theater area of the forum where folks have done exactly this process, a little research and reading, you should be good to go. 

Hello! I have purchased a home with a projector and recently purchased Sonos speakers (Playbar, (2), Play 1, and Amp). I would like to connect a Roku to the projector and speakers. There is an optical cable that runs from a cabinet to behind the wall just below the projector where the Playbar is mounted. There are two HDMI cables that run from the projector, through the ceiling, down the wall to the same cabinet. What would everyone recommend as the most cost-effective way to connect all of these with the fewest remotes. Thanks in advance!