The auto doesn't really turn off the amp, just the preamp section. I was fortunate enough to be able to buy a sub directly from Ron S a couple of years ago and he advised me to just leave the sub "on" as the power difference will be negligible. The BASH amps are fairly efficient, especially at idle. I don't think you would see too much of a power savings, but it you prefer just flip the switch to the off position at the end of your listening session or put the amp on a switched out or power strip that you can turn off.