Bitstream or PCM? Hw-n950, q7f

I have a Samsung q7f TV( I hate Samsung but I'm stuck with this and the soundbar [as it was cheap] and their non-existent customer service for the time being) , atv 4k connected to Samsung hw-n950 sound then to TV.

What hdmi input/output audio settings should I be using? Bitstream in and pcm out or PCM in/out?. Also I'm unable to get the 7.1.4 surround upscaling to work properly with my atv 4k(my fire stick 4k connected the same way works fine). With the atv 4k the rear speakers are really quiet and has no vocals, usually with my fire stick 4k, pc when I turn on artificial surround on the soundbar everything including vocals are distributed to all channels. Any help would be greatly appreciated. BTW I'm using belkin 48gbps hdmi cables that are grossly overpriced! Lol. I usually use monoprice ones.