I am looking for a solution that lets me use my HDMI port for audio output without extending my X screen to that output at the same time.
Apparently it is problematic to use HDMI for audio only, because it seems inseparable from video output. I can hear my music as long as the video output is on. This implies extending my screen to a second output, which is only counterproductive and I really don't want that.
When I turn it off
xrandr --output HDMI1 --off, the output is also unavailable for audio output. I found one related forum thread which basically confirms that audio only is not an intended use case. So I need to create this effect.
I can think of one or two cumbersome approaches, but I really hope someone has already satisfactory solved this problem. How can I use an HDMI output for audio without having to extend my screen to that output as well?