Hi. First, the Sonos app is a remote control for the system. The app does not play music. So whichever app you use, the music goes from the source to the speaker(s) and does not go through the controller device. 

If you are playing a stereo source you should get stereo.  How and where are the speakers positioned? How far apart?  

 When you say “Switching to some other app outside of SONOS”  what app are you referring to and how do you connect to the stereo 100s with that app?

Thanks for the questions!!!  Here’s some details with answers:

My objective:  Get all audio from my devices (iPhone, iPad, PC, iMac) to play in stereo on the paired Era 100 speakers just as my BlueTooth headphones do when connected to those devices.  I don't want to think about how I get my speakers to play music - and even if I did, my wife certainly won't enjoy all the steps.  She likes music but hates computers.

Let’s say I use Spotify and Amazon Prime Video (movies) apps.  

My SONOS configuration:  I used the SONOS app to configure and pair the Era 100 speakers. The Settings button (top right on the app) lists “Living Room” as “Stereo Pair”, so that’s how the app named my two speakers.  I don’t see them individually (except using the SONOS app’s System page). I will move the speakers later.  For now they are about 15 feet apart in my living room, nothing in between.

My devices:  two iPhones, two iPads, a PC, and an iMac.  I see "Living Romm" under AirPlay on my iPhone, iPad, and iMac.  I'm ignoring the PC here, but hope to get it to work too.

My iPhone's SONOS app:  The app has a section “Your Services”.  I used the “Manage” link there to add Spotify and Audible.  SONOS Radio was already listed under “Your Services”, so it now shows Spotify and Audible.  I also have the Spotify and Audible apps on my iPhone.  With the SONOS app, I select Spotify and can play any music.  As already mentioned, using Spotify within the SONOS app the music plays in stereo - BUT ONLY if this is done after I unplug the speakers and plug them in again.  The speakers play stereo as long as I use the SONOS app to switch music or even go the SONOS Radio within the app.

My iPhone's Spotify app:  When I open it, I get a notice to use AirPlay with "Living Room".  It seems most (all?) my iPhone, iPad, and iMac apps use AirPlay to connect to the Era 100s.  Let's say I am listening to Spotify music in stereo that was launched from the SONOS app (see above).  If I open the iPhone's Spotify app, I see that song is playing.  If I use the Spotify app to switch music, the stereo goes away.  The music plays mono again and on one speaker.  The speakers will not play stereo again, even if I go back to Spotify on my SONOS app.  At this point, I unplug/replug the speakers to get stereo.

My iPhone’s Prime Video app:  I connected it using AirPlay too, same as Spotify app.  Never get stereo using that app.  There’s not a way to connect Prime Video to the SONOS app as one of “Your Services”.

I appreciate the suggestions.  I’d like to keep these speakers.  They sound great.

Thanks for all tbe info. 

Sonos isn't designed to play 'all audio" from a device. It is designed to play audio files and streams from local and network sources.  Airplay gets around that for iOS devices and to a lesser extent for a Mac. Bluetooth is an alternative for 'all audio" for all your devices, and the only one for a PC.

As well as using the Sonos app, you can cast from some other apps, including Spotify.

I think you are already on top of most or all of that, but I thought it was worth a summary. 

Most, probably all, of these sources will be in stereo and you should be able to play in stereo without problems.  Even if mono, both speakers should play.  I have Era 100 and Era 300 stereo pairs that work fine.

So in your case we can't rule out a hardware fault, but we'll come back to that. 

A network issue is also possible. This does not mean your network is faulty, but may need to be tweaked to accommodate Sonos. 

First, check for updates to make sure you have everything on the latest version. 

Do you know which 2 4GHz channel your router is using? It should be 1, 6 or 11. Please try these in turn to see if it helps.

Do you have a dual band router, I.e. also has a 5GHz band?

Do you have any other network devices such as access points, switches, mesh speakers etc? 

Please try putting the speakers closer together, purely for experimental reasons - but this should not be an issue. 

If this leads nowhere then tbe best thing to do will be to submit a diagnostic just after the problem occurs then call Sonos Support with the confirmation number. 

John - Thank you.  I will be trying the diagnostic approach you mention.  Both speakers and my SONOS app and also IOS are current as of yesterday.  While I cannot say the network isn’t an issue, I haven’t had issues with any other devices using it.  It has both 2.4 and 5Ghz.  The Era 100s are connected to 5GHz.  For a test, I switched them to 2.4GHz.  No difference.  They switched back to 5GHz when I unplugged/replugged them.  All this with the speakers set less than 2 feet apart.  My network has one router, nothing else.  It sits across the room.  I’ve not had any issue with the speakers cutting out or dropping the signal.  If I only used my iPhone’s SONOS app to access Spotify, I would have no issue.  All other devices and even my iPhone’s other apps play on one speaker only.  That’s why I’ll be doing the diagnostic.  Your help has been great.  I’ll update this in a few days once I have time to work with SONOS support.

 Excellent detailed answer.  I am confused about the need to unplug the 100s before you can get stereo back.  Maybe because they were playing from only one speaker prior to the attempt to play from a known stereo source??

 Also don’t know why you are being prompted to use AirPlay when using Spotify Connect.  That should be a WiFi connection.  I am playing to a Move stereo pair at this point using Spotify Connect and it’s playing both speakers in stereo.

Hi @RESLCS .  Given all you have said and tried, I think a diagnostic is the correct call.  Make sure you do the diagnostic within a few minutes of a problem occurring.  It is probably worth doing 2 or 3 to illustrate what happens when you switch apps.  You will need to actively pursue this over the phone -  Sonos won’t contact you.

This really should not be happening and must be very frustrating.  I’ll be interested to hear the outcome - I very much hope that is a resolution to your problems.

Thanks all. 

John - I had a text chat with Sonos Support this morning after running the diagnostic.  They captured the issue and somehow monitored the speakers (I think).  I checked the router channel (automatic selects 6 for 2.4 GHz, but uses 55 for 5 GHz).  Eventually, Raymond asked me to call in for phone support who will have all the information he captured.  I’ll do that “later” (perhaps tomorrow).

MoPac - I have exactly the same confusion about unplugging.   It’s dumb that it’s needed at all.  It’s even more dumb that the speakers play stereo the first time using the Sonos app (Spotify, Sonos Radio, etc) but stops playing stereo once I use any other app or device.  Clearly this isn’t standard operation.  Something’s wrong.  I’ll get it fixed with help from Sonos Support.  It might require a replacement set of speakers?  As for AirPlay vs WiFi, I see on my Spotify app that I can choose either “Living Room” (presumably WiFi set up using my Sonos app) or “AirPlay”.  Regardless of which I choose on the iPhone’s Spotify app, there is no sound coming from the right speaker ever.

Ross

After two different calls today, each at least an hour…

I had Era 100s connected to my 5GHz network.  Switching to 2.4GHz allowed the whole issue to be resolved (for now???).  I’ve used other apps on my iPhone and iPad.  I will check the iMac and PC later.

The first attempt got me to the point of shutting off an Apple AirPort backup device.  We thought that fixed things (because the system did play stereo correctly - until I unplugged and moved the speakers to their right location).  I don’t think that device was the issue any more.

The second Sonos Support (Steve) had me unpair the speakers, then group them.  Only one speaker would play even though both were selected in the group.  I could play on either speaker by selecting it alone, just not both when grouped.  That convinced him something wasn’t right with the setup.  Switching to 2.4GHz happened shortly after that.  I used the Sonos app to remove the existing network, unplugged the speakers, plugged them in again.  They found the 2.4 GHz network themselves.  I also needed to switch my phone and iPad to 2.4 GHz.  Oh well.

I’ve had plenty enough of this for now.  I am hoping this is the final answer.  Thanks all.

  Not sure this would make much difference, but do the 2.4 & 5 WiFi have the same SSID & password?

There are some routers that don’t “bridge” the two frequency bands, i.e. they don’t allow data to pass between 2,4GHz and 5GHz bands.  For the vast majority of devices connected to your network, this doesn’t matter.  Your smart TV doesn’t need to talk to your smart refrigerator.  But because Sonos requires constant communication between speakers and with controller devices, this can be a problem.

I am not convinced that this is the full explanation, but it might be playing a role.  

Update:  The paired speakers are working great now that they are connected to the 2.4GHz WiFi.

gripe:  It took me hours to resolve this, all for lack of a simple mention of this in the “connect speakers to your WiFi” setup step.  Not even a “some users have reported best results using 2.4 GHz”.

Thanks again to everyone’s help getting me to correctly connecting and using these paired Era 100s.  I will keep them.