Cheers for that.
As you confirm that the Pro box can deliver Dolby Atmos, anybody who only has ARC, but has a soundbar with an HDMI input, should definitely connect things your way, and not as Richer Sounds describe.
I think that with eARC, it doesn’t matter if you connect the Pro box to the TV or to the soundbar HDMI, as far as audio goes, so that comes down to whichever arrangement is most convenient as regards switching inputs and the number of remotes required.
Some soundbars don’t have an HDMI input though (I’m looking at your premium £900 model, Bose), so that option isn’t available to those who own such a soundbar.
I suppose it would be helpful if we all said what we were using; mine’s an LG GX TV with the GX soundbar, both eARC, one HDMI input on that, with the audio from a Panasonic UHD player fed to it: no Pro box, but a T4000 plugged into the TV, a Roku Express 4K, and the UHD video.
Many thanks everyone.
Just for clarity, my equipment will comprise of
Samsung QE55S90C TV & Samsung HW-Q600C Soundbar, which are both eARC compliant, and actually merge speakers of both soundbar and TV to create what they call Symphony sound, and only use one remote. The soundbar does have a single HDMI input as well.
Plus the new BT TV Pro box when it arrives
I also have a Sony DVD/Blu ray player, that I rarely use but will also be connected.
I have a Sony XD93 TV with a Sony HT-XF9000 soundbar and Subwoofer with one hdmi port connected to the tv and the other connected to the BT TV Box Pro, also have a Firestick 4k Max, a Sony DVD player which isn't often used and a XBox One.