A:Answer Yes, the ARC must to run on the S2 app. If you have your products registered with Sonos, you can log into Sonos, look at the system page and confirm that your existing devices are compatible with the S2 app. Most of my system is from 2014 and is not compatible with S2. I have some Connect amps that were purchased in 2018 that are compatible with S2, so you really need to be sure before you get the Arc. I wound up logically distributing my equipment and then doing some upgrades. Now my speakers outside are on old equipment that runs on the S1 app and the inside equipment (including the ARC) are on the S2 app. Bottom line the is anything you group together has to running on the same app.