The only way I have been able to get full channel separation is by having hdmi to bitstream and then audio format as dolby digital. I then set my audio input devices such as my ps4 and kodi to pass through all audio via bitstream. My kids are watching the TV at the moment but I will run a 5.1 test shortly and post about any changes. There have been no updates though so I'm not expecting any change.
If you are outputting audio via hdmi your hdmi output has to be set to bitstream. Audio format can be set to PCM.
If you are outputting audio from a bluray player you want to select PCM for greater compatibilty with av receivers.
It depends on the source.
If you are inputting an audio source from a bluray player, hdmi audio output and format can both be pcm. In fact if i select pcm hdmi audio out my cable box will only recognize 2ch pcm and my system will only play 2ch stereo. If I play a bluray and select pcm/pcm on tv audio settings get what sounds like lossless discrete 5.1. If I switch the source from bluray to cable box while watching a bluray, I will get discrete 5.1 from cable box with tv audio set pcm/pcm. It is clearly a less compressed version of DD 5.1. If I open cable box guide or change to certain channels it will revert to 2ch stereo.
The k650 cant process raw pcm signals but it can pass them. Just like it cant process anything more than dts 2.0 but it can play dts5.1 .
If I set my bluray player to output unprocessed bitstream, I do not get good sound from either dd or dts movies.
PCM that gets passed through the TV will definitely only be 2 channel. The sound bar will then create a surround sound stage In a similar way that dolby pro logic used to. You can test this by playing a 5.1 test file. Each test tone should play separately through its respective channel with no cross over. If you hear the front left and right channels while the rear channels are playing then the soundbar is making a fake surround effect. On sound bars that support dolby atmos you have to go from your audio source to the soundbar and then from the soundbar to the TV via hdmi. The reason for this is that currently no TV's are able to pass through PCM multichannel.
If you keep saying that you will never learn anything.
Do some research, if you are outputting audio from a bluray player you want to output pcm.
Go to some audiophile sites and check for yourself. Dont take my word for it.
DTS is a movie thing, the soundbar doesnt need to be able to process DTS signals because if the soundbar needs to process anything it would be music from a cellphone app or something. Doubt there is much music content that is DTS. When the soundbar is connected to tv it is just another speaker that will output whatever sound it is told to output.