how to properly group 4 speakers together

The most you can have is a stereo pair in a room. It’s never (to the best of my knowledge) been possible to have 4 speakers in a room (other than a home theatre setup). But a room name is just a label, so to have two pairs of speakers in the same physical room is perfectly workable, and to group Room1 and Room2 is also workable. 
 

There is a new feature called zones, but I believe that only operates with multiple mono speakers. 

To create a permanent Group open the Sonos App > Cog Wheel (upper right) > Scroll down to Groups > + Create a Group > Select Rooms > Create a Group name > Save

To play the Group click the Speaker icon in the “Now playing screen” > Select the Group you created > click Apply

The group will fall apart with every restart, say after an update.

You could look at the new feature of Sonos zones, but zones do not work with stereo pairs. See 

I’m not sure I follow your comment that the group will fall apart under the circumstances you mentioned. I setup a Test Group months ago. There have been updates and even instances where I have deleted the app on several occasions and it’s still in tack. However, you may be correct if a restart or factory reset (FR) were performed. Although I’ve had no need to restart nor FR my speakers to test that hypothesis. Frankly, I’d be curious to know why an OP would need frequent restarts. To me that suggests a network issue. BTW…I have iOS and Android devices and the same is true for both. 😊

I think groups fall apart after a power failure, but not an update. That’s been my experience, having more frequent than I like power issues at my home. When there’s an update, my system stays ‘grouped’. 

I’ve always understood it to work this way, but I do not use grouping that often and certainly do not leaves groups overnight, when this would happen. But indeed turning the power off on them will ungroup them: 

• How to prevent Sonos rooms from becoming ungrouped?

I generally have 4 rooms in two groups, and I can’t recall a time where an update ‘broke’ a group. Which isn’t saying it isn’t possible, mind you. But generally, in my memory, the room grouping survives an update. Power outages (rebooting the speakers) definitely breaks the group, it’s one way I know there’s been a power outage when I’m not home ;)

​@Airgetlam​@106rallye 

I just performed a power loss test of sorts on my Test Group which consists of Era 300’s x 2 (Fireplace) and Era 100 x 2 (Garage). I unplugged the Era 300’s for 30 minutes. That was my way of simulating a power outage.

Upon re-powering the Era 300’s I observed the Test Group to still be available and have successfully started a stream. There may be several reasons why the Test Group is still in tack thus (possibly) negating the post cited by ​@106rallye:

• The simulated power outage was not abrupt as might be in an actual outage
• The power outage has be global for all speakers in the group (not just one room)
• The Sonos App has been adjusted via updates to prevent the breaking of a Group in a power outage 
• The newer speakers (post previous models) in my Test Group are immune and no longer affected by an outage 

I can’t say that any of the possiblites mentioned are the preventive measures as the question begs a definitive answer from Sonos. In any event you have my results as performed in my test. Maybe later I’ll perform the test by powering down both rooms to ascertain if the group is broken. I’ll report back.

Heh, thanks for the test. At least one comment, for whatever it’s worth. While you mention the power outage didn’t affect all your system (which I suspect is the ‘true’ answer), I also wonder if by chance (and as I type this, the less likely this seems) that the ‘grouping’ is stored on the router, which you didn’t reportedly reboot. 

You’re much more proactive than I. I’m not anxious to do any testing, but I’d be betting the ‘grouping’ is being stored by the Sonos ‘system’ on your other speakers. The reason I am experiencing my situation is total loss of power to my home, and not just a ‘group’. At least that’s my story ;)

Of course, I’ve always reported the oddity of a speaker remembering the playlist it has been playing, but not the specific position in that playlist. Every time I update the firmware on the speaker, it reverts to the ‘beginning’ song of the local playlist, stored on my NAS.