Everything I have read on this forum, and in the Sonos docs, led me to believe that I could add a Roam to my existing S1 system, albeit with limitations around sperate apps etc. This setup would not be a problem for me as the Roam would be used primarily in the garden.
To setup the Roam i unplugged all the S1 kit and then installed the S2 app. On the S2 app, i got the Roam up and running with my music services. I then set it up on my tablet, and other devices. Everything looked good.
However, when the S1 kit was turned back on, the S2 app stopped working. The S2 compatible devices had somehow automatically upgraded and were no longer in the S1 app. Now, both the S1 and S2 systems were broken. I then had to spent the next few hours factory resetting and 'downgrading' back to S1.
Over the weekend I tried to get help from Sonos support, but after 3 chat sessions were disconnected mid session, I gave up.
This evening I tried again, and this time spent 1hr 40mins on a chat session. The following is from the transcript refering to running S1 and S2 systems:
Agent: Since there is multiple Sonos system connected to the same network, the app might get confused about which Sonos system to connect to when the roam disconnects from the network. Make sure to keep the Sonos Roam connected to the wifi before opening the app so that it will automatically detects it.
Me: my concern is, what happens if the S2 app is used when the Roam is not on the network, either off or out of battery, or not in wifi range.
Agent: The S2 app will not connect automatically, so you have to check if the app is trying to connect to the existing Sonos system(S1). YOu can turn the speaker on and then close and reopen the Sonos app and see if connected to the Sonos Roam.
Me: but there is 4 of us in our household with multiple devices and levels of tech savvy. To be honest this all sounds a bit of a faff. It doesnt sound like it will work for us. it needs to be like the old system where it just worked. this doesnt feel right.
Agent: I totally understand how you feel about this. This is something that we do not want you to experience as well. We actually recommend keeping 1 Sonos system only on one network. Since there are multiple system on the same network, it is causing conflict when another system is not connected because the Sonos app will automatically reconnect to the one that is active. To actually solve the issue is to have a separate wifi network for the S1 and S2. So every time you want to connect to the S2, you'll have to switch your phone's wifi network.
Am I going to setup 2 separate home WiFi networks, and then switch between them depending on the Sonos device I want to listen to? Of course not. So the Roam is going back to the retailer, for a refund.