My SVS goes to sleep shortly after the music stops, but you can set it to stay on all in the time in the software, if you want.
Oh and you might want to turn the top end of your sub down to maybe 10-15 hz above where your main speakers start to bottom. Example, my speakers go down into the 35 hz range and my sub rolls in at 50hz, so there is only a small overlap. If done right, you shouldn’t be able to hear where the sub is.
All the best.