Originally Posted by RobinReumers
The problem is the compatibility between the Dolby Atmos layout and the Auro-3D layout. If, Dolby (which adds top rows only), wants to be compatible with Auro-3D, it will have to add the height layer (at 30° angles) to their setup.
It is already supported by Atmos. That is the beauty of object-based content. The playback processor is made aware of every speaker's position in the theater, and it automatically maps the source to them optimally, such as with VBAP. If there is a subjective difference in the spatial perception between Atmos and Auro3D, that can come down to three main causes:
1) The speakers are not optimally positioned or in sufficient numbers to create the best subjective effect.
2) The mixing engineers responded to the specific attributes of the system at hand, emphasizing its unique capabilities, resulting in a soundtrack that does not necessarily translate the intended mix optimally to other "3D" speaker arrangements.
3) Special psychoacoustic processing is added in one system's processor that is not emulated in the other's. (Such as Ambisonics or Trinnov remapping, but the possibilities are much broader.)
Also, there is a natural compatibility between all Auro-3D formats (Auro 9.1, 10.1, 11.1) which are controlled during the mix in the Auro-Codec Plug-in.
Object-based playback is inherently compatible with any speaker configuration, and unlike normal downmixing, direct rendering avoids unintended buildup of correlated sounds when electrically downmixed, thus preserving the subtle balances in the mix.
At home, people don't need the ceiling speakers above their head since in smaller rooms, the height channels at 30° around the listener are key to achieve a full immersive experience at home, similar as an Auro 11.1 system in a large cinema theater.
I have always found the putting speakers on the medial plane (other than in front of the listener) is a bad idea, whether directly behind (6.1) or overhead. Directionality is ambiguous (subject to reversals). An array of, say, 4 speakers high on the sides is much more effective. They may have to inclined more than 30° however to effectively distinguish their value relative to surrounds that are already somewhat elevated. Perhaps 45°.