Sony NPA-MQZ1K Multi Battery Adapter Kit - Manual (Page 79)

Note
If center audio is not output from the TV, enable [Settings] — [Display & Sound] —
[Audio output] — [Audio system settings] — [Acoustic Center Sync].
Connecting an AV receiver with a speaker cable (only models
with a CENTER SPEAKER IN terminal)
Connect the TV and AV receiver with a speaker cable.
(A)
(B)
(A) AV receiver
(B) Speaker cable (not supplied)
Use a speaker cable (not supplied) to connect the AV receiver to the CENTER SPEAKER
IN terminal of the TV.
When connecting, make sure to twist the ends of the speaker cable and insert them into
the connection terminals of the TV and AV receiver.