Quote Originally Posted by cactikid View Post
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.
It stands for Audio Return Channel. This means that you can plug in a video source to the sound equipment and it will pass on the video to the TV, while playing the audio directly.
But (and this is the ARC part) it will also play the audio from the TV (assuming the TV supports ARC) for any other source which goes directly to the TV. This should mean that you can use the TV remote to control the volume.

So it doesn't matter whether the duo2 is ARC compatible, as it's only the TV and the sound base/speakers that need to be. Assuming that the duo2 can send audio over HDMI - and I'd be very surprised if it couldn't. But it would need HDMI CEC support to send volume changes from the duo2 remote.