That's easy. not all bars handle all HD audio encoding. To make matters worse and why I (I'm not CNET) bother with HD audio on bars is that most TVs yell "You shall not pass" audio beyond stereo if the source is HDMI. That really upsets a lot of folk. Samsungs, in fact all the models I've ever seen are always this way. So check your TV to see if it will pass HD audio. It may not matter here.
The thing that saves this bar is that it has 2 HDMI inputs that means you can get HD audio.
https://www.howtogeek.com/304200/whats-the-difference-between-dolby-digital-and-dts-and-should-i-care/ kicks around the idea that if you get Dolby it may not matter. Especially on a soundbar.
Reading CNET review of Samsung HW-K950 sound bar, it is one of the best. However, the user reviews on Amazon, Best Buy and Samsung website are totally discouraging. The most common complaints are:
a) Lack of DTS 5.1 decoding
b) Hissing sound from rear speakers
c) The wireless speakers losing connectivity frequently
d) The sound volume from rear speakers is very low, so 5.1 sound more like stereo.
Are these concerns genuine? If someone from CNET can respond, it will be great.

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