No. Speakers have to all be on the S1 app to play an S1 stream.

Ah ok. Is this not a bit odd considering the rationale for S2 was to allow compatability with more music services etc. than S1 hardware could support. Surely playing an S1 stream (albeit with no control over it other than volume) would be pretty basic / obvious here?

Hi. What is an S1 stream, please? 

By S1 stream I mean music currently playing on a Sonos S1 system zone or group. Apologies I should maybe have explained this more clearly. 

In order to group S1 and S2 rooms together to play the same stream, both the S1 and S2 units need to recognize/identify the other unit(s) in the group.  Since the S1 units are memory bound, there is no room in the S1 firmware to add the support for the new S2 units like the Arc or Roam.  Which is the reason for the S1/S2 split in the first place - S1 doesn’t have enough room to accommodate new devices and/or functionality.

Yes, I get that S1 doesn’t have the capacity to do this, however, surely an S2 system could detect that an S1 system is already playing on the same network and “lock on” and play this stream.

The S1 system would be effectively unaware of this, but the net effect would be that the two systems would operate as one. 

This is absolute gibberish.  Nonsense. Meaningless 

There is no such thing as an "S1 stream" . There is a music source playing on a group of speakers within a Sonos system.  To play on other Sonos speakers they have to be grouped.  That is how Sonos plays synched music. It is fundamental to the system design. 

So Sonos cannot play across two systems; not even two S2 systems. Certainly you cannot group speakers from S1 and S2 or that would completely negate the purpose of having S1 and S2.

Sonos does not work that way.  Put a different way, Sonos never designed the S2 system to allow users to select “S1 system playing on the same WiFi network” on the same network and play that instead TV, aux input, or a streaming service.  There are numerous issues with that.  For one, it would be difficult if not impossible to keep the music in sync, since the S1 system would not be aware that it’s to play in sync with another system.  Two, what if there are more than one stream playing in the S1 system?  How do you identify them and properly pick up which stream you wish to play?  Three, I’m not sure you can just easily hijack data being transported from one device to another, or a net as the case is with Sonos, particularly when it’s Sonosnet and not your actual Wifi.  Four, if you’re an Apple user, this would be much better accomplished by using Airplay, I believe. So, most of your customers are no longer using S1, many of those don’t also have an S2 system, and rougly half of the remaining already have a solution...and the number will always get smaller.  It’s hard to argue that such a feature would drive product sales, or worth charging a subscription fee over. Does it really seem like a wise development effort for Sonos to pursue?

Apologies, didn’t mean to cause any offence. 

Presumably when I play something on my S1 system, the master unit streams whatever I am playing to the other units in the group, along with some sync information. This is what I mean by an S1 stream, I accept it may not be official terminology but I would be surprised if there is no such thing. 
 

Assuming (I may be wrong) that sonos didn’t start from scratch with S2 and used some of the existing code from S1, it doesn’t seem like it would be technically all that difficult for and S2 system to play whatever music is already playing on S1 in a similar fashion to how it would play what I am playing on Spotify on my ‘phone.
 

Commercially there may not be a huge benefit from this, other than S1 diehards might but S2 devices to supplement their existing system. 

Not the way it works.  For the S1 unit to play in sync with the S2 unit, careful timing cues are communicated between the two units, and these timing cues need to go both ways, from S1->S2, and from S2->S1. Thus the S2 units need to support the S1 units (easily done) and the S1 units need to support the S2 units (impossible for the Arc/Roam).  Since the latter is impossible, S2 cannot “lock on” to an “S1 stream”.  .

I’m afraid you have a fundamental misunderstanding of how Sonos actually works.  

I’m more than happy to learn!

Assuming two way communication is essential for sync (what does this acheive - presumably the master unit can’t slow down playback if the syncing unit can’t keep up) then could the S2 unit not simply mimic an S1 unit?

@t999,

One way to stream the same music to both S1 and S2 systems is to use Apple Airplay2 (I sometimes use Apple Music and Airplay from an iPad)  - but that requires a compatible speaker (a Sonos One for example) to be available in both systems and target them both with the same playing stream, but a note of caution, the streams can occasionally go out of sync, but it’s not a bad workaround - I use it myself occasionally.

Attachment shows one speaker selected from each system for playback.

Not quite the way it works, but either way Sonos is not going to release a system where only a few devices can be a master, it is not going to happen.  Plus, grouping is dynamic, so any device needs to be able to take over as the master if the master device is taken out of the group. 

For instance, stream is playing on Roam.  You group in the S1 device, Roam is the master.  You then ungroup the Roam, streaming is now playing on the S1 device.  S1 device is now the master.  Now try to regroup the Roam.  Guess what?  You can’t.

Can you see where this would be a logistical nightmare?  And that is just one example, there could be dozens more.  The disclaimers Sonos would have to publish would be 6 pages long, and that is only if “simply mimicking the S1 unit” were possible, which it is not.

This sounds like a pretty good workaround, thanks!

Not really what I am suggesting. I would see it more as a sort of digital line out → line in.Pretty sure I’ve seen elsewhere on the forum that this works and if so would imply this is possible at least in theory.

Do you work for Sonos? If not can you point me in the direction of more technical info on the protocol?

I don’t think they publish much, probably due to other companies trying to steal their efforts, on protocols. They do, however, publish the API that all services inside the Sonos controller use at the Sonos partners page.

Yeah that seems reasonable - the posters above seemed to be claiming in depth technical knowledge of how the system works so I was wondering if this was from having worked for Sonos or if there was info available online somewhere. 

No, it probably comes from over 10 to 15 years of providing support here in this forum, and a good understanding, through usage and experimentation of the way the system works. 

All who have replied in this thread have rather extensive user knowledge, and have been shown to be extremely helpful in these forums. 

Many of them are, to my knowledge, engineers of some type, who have a good working knowledge of the way that the LAN works. 

Ken_Griffiths’ comment was certainly very helpful.

“ I’m afraid you have a fundamental misunderstanding of how Sonos actually works”

“This is absolute gibberish.  Nonsense. Meaningless“

maybe not so much so! Perhaps the posters were having a bad day.

No I stand by everything I said. When using Airplay you aren't even using the Sonos system. 

There is no such thing as an 'S1 stream". It is a meaningless concept. 

Nothing you have written on this thread has made sense.

This statement just reinforces the fact you have a fundamental misunderstanding of how Sonos actually works.

t999,

The SONOS players extensively talk to each other over the network in order to maintain synchronized play among members of the Group. The originator of the Group becomes the Group’s “Coordinator”. All traffic for the Group flows through the Coordinator. In addition to the music, all players constantly share timing information with each other and are fully prepared to deal with a change in the network, possibly due to wireless interference or a player being added/deleted/powered down, etc — or removing the current Coordinator from the Group. (Think of this as changing socks while running.)

Network technology is constantly changing and responding to a change would be different in S1 and S2 as S2 evolves to take advantage of the new technology and S1 does not evolve. I realize it’s annoying and contributes to the landfills, but obsolescence is not unique to SONOS. How useful is a 15 year old cellphone or an old Apple anything? I had to recycle a perfectly functional cellphone because the local cell towers stopped supporting it. I agree that there are some annoyances, but continuing to accommodate older units with S1 is almost unique among consumer electronics manufacturers. Going forward there will eventually be some old age failures and one would need to find replacement S1 units on the used market, but I expect this will be a viable strategy for many years.