Why is the input selection from my sound bar changing automatically from HDMI to Optical [OPT]?

When playing TV sound on this sound bar model, a connection using a digital optical cable [OPT] is recommended. As such, by design, [OPT] is the default setting for the TV audio input of the sound bar.

If your TV does not have a digital optical output port, a connection using  HDMI with ARC (Audio Return Channel function) is required. If that's your case, change the [TV AU] setting on the sound bar to [HDMI]:

1. Press [MENU] on the sound bar remote control to turn on the menu on the front panel display
2. Cycle through the setting items until you reach [AUDIO] and press [ENTER]
3. Cycle through the setting items until you reach [TV AU] and press [ENTER]
4. Select [HDMI] and press [ENTER]

NOTE: If your TV does not have a digital optical output port nor a HDMI port featuring ARC, you will have to use an analog audio cable.