You can use the following two methods to play back audio in ZONE2.
Connection 1: Connecting using a speaker output terminal
When “Assign Mode” is set to “ZONE2” in the menu, ZONE2 audio is output from the SURROUND BACK speaker terminal. link
Connection 2 : Connection using an external amplifier
The audio signals of this unit’s ZONE2 audio output connectors are output to the ZONE2 amplifiers and played on these amplifiers.