A subwoofer is a loudspeaker designed to reproduce low-pitched audio frequencies, typically below 200 Hz for consumer subwoofers, below 100 Hz for professional subwoofers, and below 80 Hz in THX-certified systems.
Subwoofers are used to augment the low-frequency response of larger loudspeaker systems and are often used in home audio systems, car audio systems, and professional sound reinforcement systems.