SoundTouch speakers have an inactivity timer that will put them into a low power mode after 20 minutes. At home I use a Chromecast Audio with my Bose SoundTouch 10 over AUX. In this case and with other always-on audio devices such as the Google Home or Amazon Alexa, this feature can be incredibly frustrating.
Fortunately these speakers come with a simple shell that Flarn2006’s Blog discovered. To disable this timer you need the IP of the speaker and a Telnet client, built-in on most *nix systems including macOS.
$ telnet <device_ip> 17000
> sys timeout inactivity off