Sonos One SL S1 compatibility

Could Sonos or anyone on this forum please offer a means of identifying -- perhaps by serial number sets -- which One SLs are compatible with the S1 app/environment?

There is a lot of confusion/misinformation circulating about SL/S1 compatibility.

It appears that One SL units produced after around May 2020 are not compatible with S1. I learned this the hard way after buying a One SL. Through multiple setup attempts my S1 app repeatedly alerted me that the One SL will only work with S2.

This Gizmodo article reports that only pre-5/20 One SLs work with S1: https://www.gizmodo.com.au/2021/05/the-new-sonos-one-sl-is-a-reminder-that-smart-devices-have-a-short-shelf-life/

I would like to purchase one or more used SLs for my S1 Sonos environment but have not yet figured out how to identify pre-5/20 units. I’m sure a great many Sonos customers would benefit from this information. 

Beleza Tropical,
I think you may mean May 2021 (perhaps)? - I think any Sonos One SL manufactured in 2020 is/are S1 or S2 compatible. I’m not sure about any potential changes recently (not seen that)?… In any event, the date (year/month) of device manufacture is shown on the bottom of the speaker, near the start of the serial number.

Based on the message below from Sonos, it’s my understanding that since May 25 it is not possible to add an SL to an S1 system regardless of when the SL was manufactured.

One SL products registered from May 25 will only run on S2

In 2020 when we introduced our new operating software S2, we committed to supporting customers’ older products on the legacy software we now call S1. Those products still work today as they did more than a year ago, and we continue to keep them updated with bug fixes and security patches. 

One of the limitations we were clear about was that products launched after June 2020 would only be available on the S2 app. In May, we’re releasing an update to the Sonos One SL that reduces waste, improves recyclability, and delivers efficiencies in power consumption. While there are no new feature benefits that justify releasing it as a generational update, some hardware and software changes mean that customers will no longer be able to add One SL to an S1 system. Only new or unregistered One SLs will be incompatible with S1. This change will not impact One SL products that are already integrated into S1 systems.

What does this mean?

Starting May 25, new or unregistered One SL products cannot be added to an S1 system 
Any One SL currently on an S2 system cannot be downgraded to S1
One SL products running S1 firmware in an existing S1 system are not affected.

@ Early Rejector, Thanks for sharing that. Is it possible that One SLs registered before May (2021?) and used with an S1 system could be added to a different S1 system? (E.g. if I bought such an SL could I add it to my S1 system?) Or, can they only ever be used as S1 devices with their pre-June systems/owners? 
 

@ Ken_Griffiths, I don’t see any manufacture date on the bottom of mine. “2012” is part of my SN, but that’s clearly not the year of manufacture.

‘2012" …I did mention it shows (Year/Month) … so I’m thinking that might be December 2020, perhaps?

Note you cannot create a ‘new’ S1 system with an S2 compatible product and I think to create one with an S1 only product, you may need to remove the S2 controller app from the setup device - if you perhaps want to also keep those things in mind aswelI?

I guess it’s a case that these things are also subject to change with each new update of the Sonos software, firmware, or hardware too.

@early rejecter I’m attempting to add a One SL to my existing S1 network, with Sonos Connect. I have never used the S2 app. I don’t know whether the prior owner had my SL configured with an S1 or S2 system, in case that turns out to matter. (Since Sonos no longer allows downgrading devices from S2 to S1.) In any case, I remain unclear whether an S1-configured One SL can move to a different S1 network.

Thanks, @Ken_Griffiths. If that’s right, my SL is plausibly compatible with S1, independent of whether that’s actually permitted by Sonos.

So have you cabled the One SL to your main router, factory reset it and waited until you see the flashing green status LED and and than tried to add it to the ‘existing’ S1 App setup using ‘Add Product’ in “Settings/System”? 

@Ken_Griffiths Yes. I tried this several times. In the end the S1 app tells me the One SL cannot join an S1 network.

The person who sold me my device says it was set up with the latest Sonos app (ie S2)

My experience seems to confirm that a One SL may no longer be changed by user from S2 to S1. However, still looking for a way.

Also, remains unknown whether an “S1 SL” could be moved to a new S1 network.