The subwoofer in my setup is self powered (60 watts) and remains on all the time, unless I remember to switch it off. I've been wondering how much power I'm wasting when I forget to turn it off. I'm guessing it'll still be using the full 60 watts regardless of no analogue signal. I do have the volume down by about 30% on it. Who else remembers to switch the subwoofer off?