You already have the maximum speakers in a home theater ‘room’ in the Sonos software…although you could potentially add a second Sub.

But your Amp is already bonded as surround speakers, so you can’t add any more surround speakers. 

You could unbond the Amp from the PLAYBAR, and use the Amp for music purposes, and then you would be able to bond the One SLs as surrounds in the Home Theater ‘room’. 

Thank you. I suspected so too.

But can I also not use it as a group even if it is not bonded as one room? 

ie group HT speakers and Stereo Pair of SLs

You can always ‘group’ Sonos rooms. There is the caveat that the content from the digital input (the TV) will get delayed by at least 75 Ms when played on any ‘room’ that is not part of the home theater room, so that Sonos can ‘buffer’ it in order to play simultaneously in all other rooms. However, when streaming music, and not the Tv input, all ‘rooms’ will be in sync. 

Thanks Bruce.

I do appreciate the small delay. And most likely it may hamper the cinema experience. But want to give it a go anyway.

I have tried the grouping but it isnt working. I get error message as outlines above. Please let me know if any solution. Nonethless, truely appreciate your response such quickly.

Ok, so we are ignoring the attempt to add them as surrounds, and they’re now set up as a stereo pair in a separate room? Can you stream music to them?

Yes.. not looking to add them as surrounds.

These are set up as stereo pair. Currently kept in the same room but is set as a separate group on Sonos App.

And yes, i cam stream music to them independently. But can not stream music from One SL to HT and vise versa..

The above looks right, you have two rooms in the controller, one the Home Theater, and one the stereo pair. 

I wonder if we are getting caught up on terminology. 

You should be starting playback of music in one room, then following the instructions in the FAQ to ‘group’ the second room to the one streaming the music, after which both rooms should be playing the same thing. 

Is this process not working for you? If not, where does it fail, and what is the system showing you in terms of error codes?

When i try to play music on two different groups together - in this case HT and Stereo - i get message at the bottom of the app stating: "Unable to connect to device. Try again later" 

Happens regardless of which device i use first.

Interesting. And not normal ;)

Is your system wired with one device (or more) connected to your router with an Ethernet cable? Or are they all connected to your router’s Wi-Fi signal?

Yeah inreresting isnt it?

Amp and Playbar are wired with ethernet cable! 

Ones are connected wireless.

That means SonosNet is in use. 

The last potential solution I can think of is a reboot of your router, but that’s really grasping at straws.

Oh, wait. You haven’t turned off the radio on any of these devices, have you? I’d double check, and make sure they’re all turned on. 

And if neither of those fix the problem, perhaps someone else has a good idea ;)

At the least, I’d recommend that you submit a system diagnostic within 10 minutes of experiencing this problem, and call Sonos Support to discuss it.

There may be information included in the diagnostic that will help Sonos pinpoint the issue and help you find a solution.

When you speak directly to the phone folks, they have tools at their disposal that will allow them to give you advice specific to your Sonos system and network.

Thanks so much mate..

I will try this as last ditch effort.

Thanks again