My parents have a downstairs 50 inch Roku tv. An Element tv, so I know its not top tech. It has an arc HDMI feature and we had a small HDMI cord and plugged it into a sound bar and then had the Roku settings to have audio through the HDMI.. and no sound from the sound bar. I had a digital optical cable and that seems to work. I set the Roku tv to work with the optical and it sounds pretty good. The only thing is that I have to volume control on the sound bar. If I got a good HDMI cord instead of the cheap one I tried that can do ARC, will the Roku tv control volume through the sound bar or will it still have to have sound control via the bar?