No, the Beam does not accept HDMI audio, only HDMI-ARC signals. 

Thanks for your reply Bruce, that would be a shame, and an oversight by Sonos however I do still have the optical to HDMI option which works, so all is not lost.

It’s also a shame that they didn’t also include line-in as an option, the Beam definitely is poor on connectivity compared to some other soundbars.

Just a minor correction, the adapter that Sonos makes is optical to HDMI-ARC. Given the nature of the discussion, it seems to be relavent. 

@dazkgoodwin2 We would not disagree about the fact that the Beam would have been better if it could be used as the “Hub” for all your homecinema and musical needs. If you could connect all your devices (PS4, disc player, STB etc.) to it it would not have relied on the connected TV as much as it does now - bringing with it complaints about the ability (of the TV) to send Dolby Digital to it. Disadvantage of this would be a lot af cables on top of my cabinet though…....

We would disagree about your description for the fact you cannot (with good results) connect the Beam to a homecinema receiver as “an oversight by Sonos. This is not an oversight; the Beam simply wasn’t built and isn’t supposed to be used like you want it to. It is supposed to be connected to the TV as a 3.0 (left,mid, right) speaker and not as a part of a system also containing a homecinema receiver. I guess your not looking for a soundbar, but for a center speaker.

You mention the missing line in. Though that would have been nice (it would have saved me buying a Connect to go with my CD-player) that also would have resulted in a delay, needed for buffering on all Sonos devices.

Thanks for the reply. I realised the adaptor feeds optical to the HDMI over ARC, as a workaround for non-ARC TVs, so that's a welcome little dongle in the box.

You're right though, the Beam is intended for consumers looking for a home cinema soundbar, not to add to an existing set up, my main purpose was to extend my Sonos music set up to my lounge, and the Beam is perfect, it almost disappears in front of the TV, so I'm very happy with it. 

If I want to listen to TV on the Beam I can still do that, and turn down the receiver speakers, so I've got options. Despite the recent update controversy, I've been a very happy Sonos customer for ten years.

SOLUTION! Found it myself.. yes you can use the Beam in combo with an existing surround system, the Sonos app under the beam has a setting for TV sync delay, +2 and it’s in sync with my system. Cheers.

I use the “TV dialog sync” slider bar too, when playing stereo audio from the TV with its in-built Apps like YouTube/Spotify/Deezer/Amazon Music etc.. and grouping the Beam with several other “Sonos Rooms” (some of which are in the same physical room) as they then play the TV audio-out in “perfect sync” across all the grouped rooms. Great for watching the general terrestrial TV channels too.. that’s if you like audio coming from all areas.

How do I use the sonos beam as a speaker to my hifi Denon AVR X500 receiver? 

It can’t be done, as far as I can see, that’s from looking at the connections online on the rear of the device.