Hello!
I have been using MS650 soundbar with two R3 speakers for a full 5.0 surround configuration with UE65KS8000 tv.
Everything was fine until it updated to the 1129.1 firmware yesterday.
Now the volume on rear speakers is too low even with -6 on a soundbar and +6 on R3's set in the Multiroom app.
It's the same problem as previously addressed with HW-K650 soundbar with R speakers as rear surround (there is a huge thread about the issue here).
From what i see the volume on R3's doesn't scale linearly with the soundbar. Up to 45-50/100 volume R3's are a lot quieter than the soundbar and around 55/100 they match the output volume of the soundbar (tested with multiple surround test files) and then they suddenly become exponentially louder than the soundbar with evey step making a huge difference.
Problem is that 50+ volume is really loud, and it's impossible to watch most movies at those volumes.
It was like that pre update too but the "matching point" was at lower volume levels and you could just manually adjust R3's vs soundbar volume via Multiroom app and get a good surround sound field at lower volume.
Another thing about the 1129.1 firmware update. I have been told by a Samsung salesman that MS650 is getting a full DTS 5.1 support this year. I guess that was the point of the update (can't be sure since you are not giving us any changelogs sadly), because the system can now play DTS 5.1 with all channels being properly separated, but only via HDMI ARC connection. With Soundbar being connected through WiFi to KS8000 im only getting fake DTS surround.
Is that a technical limitation or simply a bug? Dolby 5.1 plays correctly via both WiFi and HDMI, but again the rears are very quiet.
Can any of you dear moderators pass this to the team that was working on a fix for K650+R speakers problem?
Thanks in advance! 
Hello!
Netflix and the rest of streaming services use Dolby. If your soundbar is connected to your TV through ARC, you need to set HDMI audio format to Bitstream and Audio Format to Dolby Digital in your sound settings. You have to do this WHILE THE MOVIE/SHOW is playing not in the Netflix menu, so the TV recives Dolby signal.
Bear in mind that every time you watch something with DTS track from your Bluray or NAS, you have to manually change to DTS in audio format (also DTS 5.1 only works through HDMI connection, it doesn't work with WiFi), and when you get back to Netflix you have to switch to Dolby etc.
F8000 is the older tv running Smarthub right? I have KS8000 with Tizen so your menu might be different and ARC connection might work different on it. For example all the new samsung TV's (QLEDs) can't output DTS through HDMI ARC and Optical, so you can only play Dolby (it has to be some kind of licensing issue).
Oh and sometimes Primevideo (amazon VOD service) bugs out for me, and in TV settings i see PCM, like you said (and im unable to change it), with sound being messed up. Restarting the movie usually solves the problem.
Never happend to me with Netflix though.
Glad i could help
>Should the rear speakers be outputting dialogue? When I put my ears to the soundbar I can only hear dialogue from centre, and effects from the left/right.
Usually with surround mixes conversations of characters talking on screen will be played only from the center channel (sometimes a little left/right too), rear speakers are usually playing ambient sounds, music etc. or sounds that are positioned "behind the screen".
Sometimes you can hear voice from rears, for example when some powerful "psychic" character uses his alien voice 
It all really depends on a movie/tv show. Some tv shows like The walking dead barely use rear channels, and some use them a lot.
This is a basic dolby channel test check:
https://www2.iis.fraunhofer.de/AAC/ChID-BLITS-EBU.mp4
I used it to adjust the volume on SWA9000 rears, because all the spoken commands are at the same sound level.
You can download it and play it from a pendrive on your tv. It's the easiest way to check if channels are properly separated.
Theres also a sound check on Netflix.
https://www.netflix.com/title/80018499
Yeah it's down to the source. Like i said, when you play DTS file, you have to manually switch to DTS there, or you get a fake surround. Not sure if F8000 can play DTS through ARC though.
MS650 with SWA9000 does indeed play real 5.1 DTS even though it says 2.0 on the box. It recieved an update some time ago. If you plug it directly to a bluray, and pass the video to your TV it will play DTS5.1 properly
Not sure what Dolby DIgital Comp is on F8000, but quick googling says its a method of compression used (so looks like it's always bitstream). I think you should leave it as it is.
When you see TV settings - > Broadcasting - > Audio Options - > Audio Format = MPEG, it means it's not broadcasted in Dolby
Sometimes there are multiple tracks though, even in live tv. I see some stations here having mpeg as default, but theres a hidden Dolby track too, but you have to switch to it manually.
