An active subwoofer is a type of loudspeaker designed to reproduce low-frequency sounds, typically below 200 Hz. Unlike passive subwoofers, active subwoofers have a built-in amplifier, which means they can produce powerful bass without needing an external amplifier. This makes them easier to set up and use in home theater systems or music setups. Active subwoofers often come with adjustable settings for volume, crossover frequency, and phase, allowing users to customize the sound to fit their space. They are commonly used in conjunction with other speakers, such as satellite speakers or floor-standing speakers, to enhance the overall audio experience in a room.