No, it will not.  All a factory reset does is reinitialize the current firmware.  It cannot downgrade or replace the current firmware. 

Ok, but then if I

1. do a Factory Reset
2. install an older Android app version (one which still offers the Downgrade option)

Would that work ?

Yes, do the downgrade, and then add with the S1 app. Works great for now..

@Heather666 , it’s not 100% clear for me what you’re saying `Yes` to…

A Factory Reset will actually also downgrade ?

Or I should do the Factory Reset and then the controller will work with an older Android app (Eg: 16.1) and that will be able to trigger the downgrade ?

You factory reset, then after that, you have to downgrade using an Iphone 7.

Factory Reset does not download anything and will not change the firmware level.

I only have Android phones…

Do you know if I’ll still be able to do it, with an older apk that I manually install ?

I’m still running S1, so a couple of notes for what they’re worth. (Is there a thread on S2-to-S1 downgrades?)

I’m running the S1 controller app on my iPhone 14 with iOS 17.5.1. Also on my MacBook with macOS Catalina 10.15.7. Both of those S1 controllers seem to work fine. Both are Version 11.14. I’ve seen comments suggesting that the S1 controller only runs on older operating systems. Perhaps some people have run into that limitation, but not me.

In addition to the old units (e.g. ZP80s, ZP100s, early Play:x speakers) created before S2 existed, I’m also running an Amp and two Ports. These came from the factory with S2 firmware, but my S1 app was able to tell them to downgrade themselves. But here’s an important point to note: The technical specs for the Amp and Port state clearly that they are compatible with both S1 and S2. See here and here. The specs for many/most other new-ish SONOS gear either say S2 only or don’t indicate the required app level. (At least not on the specs Web page; the downloaded documentation might say more.) For example, the spec for the Beam mentions S2 but not S1, so I wouldn’t be surprised if the Beam can’t be downgraded. Then, again, the linked spec is for “Beam (Gen 2)”. Perhaps you and/or @serban, who started this thread, has an earlier version of the Beam, and perhaps that’s downgrade-able.

Product/app compatibility here:

https://support.sonos.com/en-gb/article/sonos-app-version-compatibility
 

Downgrading devices from S2 to S1 is one of the next things Sonos is rolling out on their app updates.

@nik9669a Great reference, thanks! Now bookmarked.

@Rhonny Thanks for that info. I would assume only the devices that are listed as S1-compatible could be downgraded. Is that your understanding as well?

Yes, of course they have to be S1-compatible in order to be rolled back to S1.