subwoofer

A subwoofer is a type of loudspeaker specifically designed to reproduce the lowest audible frequencies. Loudspeakers, in general, convert electrical energy into acoustical signals, essentially creating sound from an electrical input. This is typically achieved by a motor, often a voice coil, that vibrates a diaphragm. This diaphragm's movement creates sound waves that correspond to the original audio signal, such as music or speech.12

Because a single loudspeaker struggles to reproduce the entire range of audible sound (approximately 20 to 20,000 hertz), different types of speakers are used for different frequency ranges. A speaker for low frequencies is called a woofer, while one for high frequencies is a tweeter. Subwoofers are specialized for the very lowest end of this spectrum.2