That Denon has two optical outputs, so just connect the Playbar to one of those.

Hi @mpohlkat.

Welcome to the Sonos community and thanks for reaching out to us. I understand that you wanted your Sonos to work with your projector. Allow me to share with you some information to help out. I would also like to provide an information, your Sonos Playbar is already your front left, center, front right. By default the Playbar is already (3.0 home theater system) add the Sonos Sub and your Connect Amp as surrounds makes it (5.1 surround sound). Grouping additional Sonos Speaker to the main home theater speaker is possible however, it has delays compared to a bonded 5.1 surround sound system.

I would like to set your expectation, connecting Sonos to a projector is not a recommended set up. Sonos home theater speakers such as the Sonos Playbar, Playbase, Beam, Amp, and Arc were designed to be connected directly to a TV. However, We can always reach out to other members of the community to see if they have any opinion or recommendations on this. There might be other members of the community who may have the same setup as you and for them, the setup might be working.

Let us try to reach out to other members of the community and check their recommendations and feedback. Everybody can lend a hand.

Thanks,