@nxtoa here is my current system diagram before I mark it up for another hdmi cable order:
This monstrosity will be controlled by Harmony 665 10 device remote using tips to have simple devices not take up device slots (https://bevhoward.com/Misc/IR/Harmon....html#DevLimit
). I considered 15 device Harmony Elite which can be had refurbed for under $200 which has a hub for more reliable device control and potential to add Alexa voice control device, but ultimately the eventual hassle of replacing its rechargeable lithium batteries scared me from its purchase. The Harmony's Activities will allow the beast to be completely tamed and easy to use.
All of the video goes pretty much direct to my LG TV separate from the audio and is easy to see in the diagram (ATV4K uses AVR Key splitter and Xbox sends video through Soundbar to TV via hdmi arc.) No audio comes from the TV to the soundbar. (Have you disabled ARC on your K950?)
Main 4K Component roles:
1. ATV4K (iTunes, Infuse for 4K non-Atmos files, Vimeo) - atmos dd5.1 sent to Oppo/Xbox for Atmos upmixing and sub. Potential future Atmos use via audio split direct to soundbar and subwoofer extracted by Oppo.
2. Xbox One S (insects demo, Netflix HDR/Atmos, FandangoNow DTSHD (HD video only), DTSHD 4K disc playback, non-Atmos bluray playback, HD file playback) - via its input is the Atmos upmixer for the system. Its main role is for DTS HD playback which it upmixes to Atmos. Doesn't play 4K files. (For those who want the best fidelity for HDR/DTS content disc playback an option on this, but the Oppo will have better video quality).
3. Sony UBP-X700 (Vudu DV/Atmos playback, youtube HDR, Amazon HDR/DD+, Netflix DV/upmixed Atmos) - note that this unit has some file playback capabilities.
4. Roku Prem+ (FandangoNow HDR) - this unit works well with Oppo's hdmi input. HDR iTunes titles that port to FandangoNow get DD+ sound output instead of dd5.1 and the Roku also seems to play HD Fandango content better than most any other service/device combo.
5. Oppo (4K disc and file playback) - not great for DTSHD as its only does DTS and Xbox won't even accept this format for upmixing. On Samsung K950 Sport audio mode does a great job with DTS and best option for DV/DTSHD playback. The Oppo of course also provides the analog subwoofer for the extra subs and some form of signal for every source must come through its hdmi input.
6. The Toshiba and Pioneer are disc players and for non-4K dolby Atmos blurays (not common) may use Pioneer as its rumored to exceed Oppo's video quality. Regular bluray playback only gets DTS direct to the soundbar vs the Xbox's upmixing of DTS-HD MA to Atmos. The better overall combo may vary from disc to disc as the Xbox does not seem the best disc player based on my casual experience. The Toshiba handles some defunct HD DVDs I own which often had Dolby TrueHD tracks which the Xbox hdmi input will accept in full fidelity. I didn't get an HDMI input with enough switches so this and the Pioneer will share one cable to switch back and forth which is OK as one has to put the disc in the tray. If I end up needing a third hdmi switch for some reason I'll get one with more inputs.
My hope with all of these is to get every source able to send some kind of signal via hdmi to the Oppo for the extra subs. The oddest solution is the Revesun splitter as it looks like it sets up an hdmi loop involving the Xbox and the Oppo, but its purpose is to get signal only to the extra subwoofer when playing back from the Xbox itself. If the system had the needed 6 hdmi input switch it would have a total of 20 hdmi cables.