The text marked with this symbol that will enable after the upgrade of the Auro-3D.
You can experience the best performance of Auro-3D if you install Front Height and Surround Height in addition to standard 5.1-channel. The “Setup Assistant” will lead you to this setting.
You can use Rear Height speakers from a Dolby Atmos speaker setup instead of Surround Height speakers for Auro-3D playback.
The AVR also can play Auro-3D using standard 5.1-channel and Front Height speakers. If you install any height speakers instead of Surround Height speakers and Rear Height speakers, you can set the speaker configuration in setup menu.