I should add that I have tried this with both iOS and Windows controllers.  The Windows controller seems really cripled lately.

On iOS, open the controller, click on settings, the click on system. Click in the room name, then click in the product name, which opens up the page where you can turn off the radio.

For anyone else considering this, it is not advised. Sonos uses the radio to keep speakers in sync, and to run things that are “bonded”, such as a SUB and surround speakers. 

Thanks, found it.

I found it one level deeper than I was looking.  It is under “Amp”, which is the product name.  I mis-read this in the documentation and your response.

I was confused by the product name.  “Amp” sound like amplifier configuration to me.  at any rate, I wasn’t looking deep enough.  Seems like they could rename that section “Radio” or “Wifi” as that is the only setting here.

Thanks again!

Doesn’t this also happen over the lan port?  Seems like network topology is simplified with wifi disabled and there is a slight power savings with the radio turned off.  I would expect that so long as each player has a connection to the network, either hardwired or wifi, that sonos will be fully functional.  None of the players i just turned wifi off on, utilize subs or surrounds to test the above statement.

Thanks again.

The ‘Amp’ is the type of device in the chosen Sonos room. The reason a user finds the WiFi deactivation/activation setting at the next level, is because some Sonos Room setups, like Home Theatre rooms, for example. may have more than one Sonos device attached to it.

The challenge faced here is the variability of the knowledge of the user. While you understand the underlying process, there are many who don’t. Several times a month, we have users who show up and ask as to why their SUB, or surrounds aren’t working, without recognizing that the “Wi-Fi” name is actually the “radio” part of the device. So, if they haven’t connected via Ethernet cable, these devices just “disappear” from their Sonos system, as they are the “slave” devices to the sound bar, connected via the radio.
 

It would be nice if there was an additional warning on this page, suggesting it’s for advanced users, or professional installers, but often the people who use it don’t understand the ramifications. That’s what I was trying try to avoid with my post.

It rather depends what you mean by 'fully functional,'.  If you turn off the wireless radio on all the wired units then you are choosing not to benefit from the SonosNet mesh. Yes, the wireless speakers may connect via WiFi but that may not be optimal. And if you haven't entered the wifi credentials into Sonos, the wireless speakers won't connect at all. We've had cases like that too; it isn't just about subs and surrounds. Provided you are aware that you are foregoing the benefits of SonosNet, and are happy to do do, then fine.