I am about to sell my Zidoo Z9S to a buyer who has a marantz SR5500 which doesn't support DD Plus. Does downmix DDP to 5.1 option in the Zidoo Z9S, mix the sound as true 5.1 or just all around same thing in all speakers?
Dolby Digital+ is fully backwards compatible with Dolby Digital so any DD+ content will play correctly as DD on the Marantz.