The Sonos Amp, the Sonos Beam (both gens) , the Sonos Arc, the Sonos Arc Ultra all use HDMI ARC?

This is sonos response.(?)  Just buy another product at $1,500 at minimum (including sub-woofer and ..)

Thus Sonos is saying that ArcC and Arc Ultra. Is the new comprehensive joiner? Yes I know them.

Yes, I would like to buy either.  But then again I am still back to my original primes. Sonos does not play well with “others”.  Do either of those products propagate, appropriate surround to the other  room speakers (beyond the “back” speakers? NO.  Yes, an interpreted surround, not true surround and only to the back speakers. Just listen to any 5.1 produced movies or CD/BR from any other “room” with sonos speakers. NOT, it is stereo.

Is Arc the new Port? Maybe? NOT for me.

I’m puzzled, ​@Tim_J. In your first post you say you  “don’t know of any Sonos products that use HDMI”. ​@Airgetlam points out a few, and your reply is “Yes I know them”. You say “the market will inevitably demand a full surround sound experience from Sonos” yet they already offer 5.1 Dolby and full Atmos capabilities to meet that “inevitable demand”. 

What integration between Sonos and Denon are you looking for?

Honestly, I’ve read this three times and I still can’t figure out your complaint.  What sources over “HDMI” are you looking to play on your Denon that you can’t play now without Sonos involved? 

Also, why would anyone in their right mind need to “propagate, appropriate surround to the other room speakers”?  Surround sound is meant to be anchored to a screen.  Why would you want surround sound to be grouped in another room which doesn’t house the screen? 

If you are talking about Atmos music (which is the only content you could want to send to another room without the screen), Atmos music does play in surround when grouped, as long as if you have Atmos capable speakers in both rooms. 

Truly baffling.  I really don’t think you know what surround sound is, or you are confused about Sonos implementation of it. 

Maybe looking to have the Port send streamed Atmos tracks to the Denon?

I recall, from many years ago, setting up an SACD player to send multichannel to my Denon but that required compatible ports on both devices.

Maybe add an eARC output to the next generation Port to support multichannel output?

Actually, reading it again makes me suspect it’s just a rehashing of the old “let me add separate fronts/ceiling Atmos/side surrounds to my soundbar” request, misconstruing “propagate, appropriate surround to the other room speakers” with “let me send surround to other speakers in the room”. 

Just another “Sonos surround sound isn’t true surround sound” and “make my soundbar be a center speaker” nonsense that we’ve seen before.

Thanks for the several responses.  Frankly I feel the need to reply knowing I may not have all my thoughts completely thought out.  That said, I’ll try.

I am a somewhat of a reluctant Sonos user.  I have several 100’s, moves, and a 300 which were kindly gifted to me.  Frankly I do enjoy them.  Here is my issue. 

I’m listening to YouTube music with video in the afternoon (yes, not the best quality, it depends on how it is produced). That said, The YouTube feed comes through my Shield Pro and is fed via HDMI to my Denon and to my existing surround sound speakers.  The Denon tries to produce true surround and does a reasonable job depending on the source music. Then it’s dinner time.  Now turn off the Denon and ask Sonos to play music in the dining room.  Nice.

Back to my point, I two separate systems. 

I do also have an older (gifted) Connect (?) which feeds from Sonos into the Denon.  Not so bad. Unfortunately it does not go back the other way.  I know it is supposed to but, not.

Moving on. I see newer device the Port at a bit less than $500.  Do I trust that it will work? I’ve checked with Sonos marketing materials and certainly they promote porting Sonos music to another traditional receiver.  But, they do not fully embrace the other direction.

Here is the premise I originally mentioned. The Port only has Left and Right RCA ports.  Yes I admit that’s “red herring” point reference stereo vs surround.  But really, for $500 in our current technology, it should be HDMI. AND, I’m not fully convinced enough to spend $450 plus tax etc.

That’s just my comment and opinion.

So are you saying that you want send your TV’s 5.1 sound to two rooms, where one room (with the tv in it) uses a Denon surround system and you want the other to be a Sonos 5.1 surround system - even though there’s no video picture in the second room? 

Ideally, yes.  In reality / actual use, probably not necessary in most cases.  I admit the 5.1 is a bit extreme.  

You do know that YouTube videos are stereo only unless you are paying for the premium subscription?  Even videos marked as 5.1 are downmixed to PCM 2.0 to save space. 

As to “going the other way”, both the Connect and the Port have RCA Line-Ins.  For your purposes (playing stereo YouTube videos) RCA is sufficient to output from the Denon (if the Denon has RCA audio output) to the Sonos system in the same stereo format that is playing on the Denon.  You can then simulate surround by using the Full/Ambient setting for Music Sources in the Sonos settings. 

As to the Port getting HDMI input, I’m very doubtful that the fringe case of playing YouTube videos in another room where there is no screen is enough to push the needle.  Indeed, it is the first time I’ve ever heard this request, and there are some really out there requests in here.

OK, thanks for the feedback.  Obvious I don’t know what I’m talking about.

I just bought an Era 300 to pair with my other one.  Will stay status quo with the two separate systems.

No more feedback.

The Connect (unless broken) will go both ways with the Denon if it has available connections. I simply used my Denon's tape jacks to connect mine. 

There of course be delayed sound issues to sort but that is another topic.

The Denon might not send audio that comes in via HDM out (to the Connect) via an analogue connection. This might not be a Sonos problem.