Panasonic SC-HTB510EGK Operating Instructions Manual page 7

This system (Rear)
Main unit
Active subwoofer
A HDMI (ARC) terminal (ARC compatible) ( 8, 9)
B USB port (for service use only)
C OPTICAL DIGITAL AUDIO IN terminal ( 8)
The I/D SET button is only used when the main unit is not paired with the active subwoofer. ( 22)
6