It seems that an audio process can not go into a powersave state. I started powertop and found out that switching “Enable Audio codec power management” from “bad” to “good” did the trick.
Alsamixer shows under system information, /proc/asound/pcm “00-00: CONEXANT Analog : CONEXANT Analog : playback 1 : capture 1”. Whatever that means, I’d really like to know how to set that playback and capture to 0. Anybody here with knowledge of alsa?