Found in their Q&A section:
Denon Support
· 21 days ago
Hey G Lo, The unit provides 11ch playback by assigning all nine internal amplifiers to the receiver's main zone and using an external 2ch amplifier for either the Front or Height 2 channels. Up to nine speakers can be powered by the receiver's amplifier, while two speakers are powered by an external amplifier. This amplifier configuration is compatible with up to 11.2ch and 7.2.4ch applications. We hope this helps if not you can always give us a call to have one of our expert technical support team members assist with this and any other concerns you may have.
Thanks, Denon North America