1) The vast majority video content is not encoded with Dolby ATMOS - look for the ATMOS logo, not just Dolby 5.1 or whatever
There needs to be an update to increase the volume on surrounds. Bose had a similar problem with the virtual invisible rear speakers for their sound touch 300. Front stage on the soundbar is excellent. The rear speakers on the other hand are way too low
There are "relative" volume controls for all speakers and the sub-woofer. They can be accessed with the remote. You scroll through speaker selections that appear on scroll bar and then adjust the volume. Also, one of the firmware updates apparently enhanced rear speaker volume. So, make sure you have done firmware updates.
To further clarify the issue around ATMOS -
While there are numerous surround formats, the vast majority are designated 5.1 The 5.1 implies there is a front center, front right, front left, rear right and rear left speaker arrangement (that's five). The .1 implies there is also a single subwoofer. There are some that go further with 7.1 or 7.2, but I've never seen these listed on any video formats. ATMOS encoding does go further and could also be listed as 5.1.2 The 5.1 is the same surround as above and the final .2 implies two channels that either fire upward or ceiling mounted speakers. Obviously, in the case of the HW-K950, there are two speakers that fire upward.
Reviewing Netflix and Amazon streaming video offerings, I was not able to find any that list Dolby ATMOS or 5.1.2 audio formats - even on the 4k offerings. Almost all of them list 5.1 which could be either Dolby or DTS. So, you get real surround sound, but not ATMOS. The only time my ATMOS light goes on at this point, is when I play a BluRay that indicates Dolby ATMOS audio. If anyone else can point me to a Netflix or Amazon streaming video that lists ATMOS or 5.1.2 audio, I would be very interested in testing it out.
An excellent reference with full explanations of different formats, etc can be found on lifewire.com Articles explaining DTS Neo:6, which really is fake suround sound, 5.1 vs 7.1 vs 7.2, etc and why PCM actually would by-pass the ATMOS decoding compared to bitstream, etc........
There are many Dolby Atmos titles on Netflix and Amazon Video. Just search "Dolby Atmos". Netflix displays Atmos on the description of each title. Many of the 4K titles will show up as you scroll through…
> .I have a Sony UBP-x800 Blue Ray/4K/atmos supported player.
I do too and I was not able to get the Atmos Blue light ON and Atmos scrolling text, although I had set my Sony UBP-x800 Audio Output setting to PCM (as suggested so many times on the internet).
BUT when I put my Sony UBP-x800 Audio Output setting back to Auto, I imm got the Atmos Blue light ON on the soundbar including the scrolling Atmos text PLUS the GREAT Atmos sound finally.
So it does work for the Sony UBP-x800 as long as you set the Audio Output setting to Auto and NOT PCM.