Remote controlled electronics can never completely power down. Otherwise they would not be able to receive and process commands, but they can reduce power use by powering down power hungry sections, such as displays and audio amplifiers. Audio amplifiers require several seconds to stabilize as they startup. SONOS keeps the amplifier alive for a few minutes after the last audio is detected. This avoids nuisance audio delays that may occur if an aggressive power saver shuts down the amplifier after a couple seconds of silence. Many audio and video tracks include many seconds of silence at one or both ends.
