(Another projector question) hooking up a projector with HDMI-ARC to Beam?

I know there's a lot of these types of questions, but here goes...

I have 2 Play:1s and a Beam in my house currently. I bought the Beam primarily to get Projector or laptop hooked up. I realize that the laptop setup would have challenges as there is no output to carry audio like ARC. The projector I am looking at, however, does have an HDMI ARC output. It's the XGIMI H1.


Minor detail, but HDMI ARC isn't an output connection per se. ARC stands for Audio Return Channel. Technically, it can be used as an HDMI input the same as any other HDMI input, but it also has the capability of returning audio back to the device connected to it when there is a proper handshake between the two devices. In fact, when you connect the Beam through ARC, and switch your projector input to the port the Beam is connected to, you'll see a Sonos visualization on the screen.


Three questions...if I wire the HDMI out from the projector to the Beam, will I get sound without some sort of converter/TOS unit?


yes.


Second, will that sound possibly be Dolby/Atmos/other hifi sound?


The Beam is capable of Dolby Digital 5.1 or PCM (Stereo). When the source is Atmos, the TV is supposed to recognize that the Beam is DD 5.1 and downgrade the signal accordingly. That's part of the ARC spec. If your source is DTS (common on bluray, though some bluray players can convert to DD 5.1), you'll either get stereo or no audio. And of course if the source is stereo, you'll get stereo.


Third, does the act of connecting the HDMI to the Beam then mean that the other speakers in my Sonos network can play the projector audio?


Yes, however there will be a slightly delay in the other speakers. Not an issue at all for speakers in other rooms of the house, but possibly creating an unwanted echo effect for speakers in the same physical room (sub and surrounds excluded of course)