LG Optical Audio or Multi-channel Audio Output
The Optical Digital Audio Output or HDMI/ARC Multi-channel Audio Output is available as PCM or Auto. DTS Audio is not supported on current LG Televisions.
To set the Sound Out mode, follow the steps below.
1. Press the Home button on the remote control and select Settings > SOUND > Sound Out, then press Wheel or Enter.
Depending on the method of connection for external audio, this will be either: Optical Digital Audio Output (Optical cable) or HDMI/ARC (HDMI cable). Both of these can output either: 2 channel stereo sound (PCM) or multi-channel Dolby 5.1 digital sound.
For either the Optical Digital Audio Output or HDMI/ARC Multi-channel Audio Output, select External Speaker and then select either PCM or Auto as the Digital Sound Out.
To use an HDMI cable, HDMI 1 must be used on the TV, and the external sound system must support ARC (Audio Reverse Channel). Select ARC Mode to ON.
Select Close when finished.