In the Home Theatre room settings in the Sonos App ‘Settings/System‘ goto Surround Audio and move the ‘TV Level’ slider control over to the far right to shift the front channel audio to the rear speakers.

That just makes the rear channel louder . I want the voice from the playbar in the rear speakers . So basically 5.1 to 2.1 

Maybe switch the TV audio-out codec to PCM stereo and then adjust the slider in the App and see if that works for you. I get the news presenters voice from the rear speakers when doing that.

Ok , I’ll try that although I think I’m already in pcm but I relying on memory !! Wish Sonos had a mode button !! 

Yeah , it’s already pcm 

So if you put the news on your TV, do you not get the newsreaders voice from your rear speakers when you slide the ‘TV Level’ over to the right?

Haven’t tried the news but I’m watching idol . Rear speakers only have rear speaker sounds . Voice is in the playbar . Like I mentioned before , I only want to put it in the rear speakers for late night listening or certain programs that need the voice closer to me 

Another option you could perhaps try, is to unbond the rear speakers from the HT and stereo pair them instead and then group them with the Soundbar, but mute the soundbar, so as not to create an echo in the room. That will usually work too with PCM stereo audio. I don’t personally like this however, as the voices coming just from behind my listening position always seems a little odd to my ears.

I like the setup I have and don’t want to change it . Just want to go from surround to stereo occasionally to place all the sounds in the rear speaker so I’m closer to the voice . I’m sure for Sonos , that’s an easy extra button to slide !! 

The rear speakers should not have any audio output with PCM 2.0 stereo… it’s only the left/right front channels that you should hear from the rear, when moving the ‘TV Level’ over to the right hand side.

I have pcm , full back channel sound on the rears 

That sounds like you’re getting Dolby ProLogic II decoding, as that allows ambient audio to the rears - I would double check the TV settings are set to PCM and not Auto.

Maybe see this link…

https://audioviser.com/pcm-or-dolby-digital-for-soundbar/

"PCM isn’t built to support surround sound"

I have an LG TV too - I’ve just tested it with the news channel here and get nothing from my rear speakers until I move the TV Slider. It’s probably some sound engineering trickery. PCM 2.0 (uncompressed) is just two channels only and no separate .LFE (Sub channel) as far as I’m aware. 

If you’re getting some background/ambient audio from PCM 2.0 - then you’re likely going to hear the same ‘merged’ channel audio from the rear speakers aswell, even if Sonos were to introduce a ‘mode button’ to do this anyway.