LG S90QY Owner's Manual page 15

Surround sound function ON
When the surround sound function is turned on, sound is output from all connected speakers regardless of
whether the Multi-channel Experience is turned on or off.
Input
All Sound Effects
2.0 channels
5.1 channels
7.1 channels or more
7.1.4 channels
Sound Effects
Rear speakers not connected
Output
Rear speakers connected
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