The system is plugged into the ARC HDMI slot and switches on/off with the TV fine. So the TV has proper control over the audio system. I just wondered if there's already a voice command I can use on the TV to turn on/off the system? Seems like an obvious one that would already be part of android TV.

All I've managed to do is switch to the ARC HDMI input, that in turn would switch the audio system on. Would be nice to switch off the auto on with the TV, and then use my voice to turn it on/off without switching to it. Then I can ditch my remote for my audio system. The TV speakers is plenty for the news/youtube, use my 5.1 system for movies/music only and then save a little money doing so. With the crazy energy prices, everything makes a difference, some amps can be power hungry like mine.