What is HDMI ARC mean?
In theory, ARC is supposed to let you have one connection between your TV and whatever you use to create sound: a receiver or a sound bar. You send video to the TV with an HDMI cable, and that same HDMI cable sends audio from the TV back down the same cable. dont think duo2 is compatible so dont use it.
just plug your hdmi cable from your duo2 into a hdmi 1 input on tv .
do all connections while both units are powered off.
just reading specs on lg i would use second hdmi cable to second port hdmi on tv.
no mention of spdif/optical on the lg to run a cable between that and tv for surround sound?