Not that I know of, though it may say something in the specs.
We shut down all electronics at night unless something is doing an over night render. But certainly those speakers get shut down each night as they’re not necessary for anything overnight. We run self-powered KRK Rokit 5’s in all our suites.
there is no reason not to turn them off. It’s not like the capacitors in the power supply will be more unstable if you turn the speakers on and off, night after night.
With that said, there are some speakers (like Behringer B2031 Truth speakers) that turn off when there is no signal applied to them for a period of time. I actually hate this feature (because the power light goes off, and you think that your speakers are not working), but some modern powered speakers have this feature.
many electronic devices still draw “phantom power” even when turned off. This was a “feature” added to lessen the time it takes them to “warm up”, and turn on. This means that we all are paying for electricity, that in essence, is not being used.
When your just talking about a pair of speakers, it doesn’t seem to impressive, but think about your tv, stereo, cell phone chargers (draw power even when not hooked up to your phone), and almost everything else that you leave plugged in at your house/work.
So knowing that, its better to power things down, but even BETTER to unplug them.
I don’t follow this 100% as it is highly inconvenient, but I do what I can. To make it easier, you can hook several devices to a power strip. A power strip, when switched off, is said to eliminate “phantom power”.
The less electricity you use, the less you have to pay, and you will lessen the amount of coal that the elec companies have to burn.