History

• The subwoofer was created in the 1960s by Ken Kreisel of the Miller and Kreisel Sound Corporation as an enhancement for home speaker systems to heighten the bass presence. Steely Dan was the first band to utilize the subwoofer in a recording session with its 1973 album "Pretzel Logic," and the device was adapted by Hollywood the next year for the first Sensurround film, "Earthquake." Sensurround utilized large subwoofers to produce minor vibrations and deep tones to enhance the film's experience. The subwoofer gained Main Street popularity in the 1980s as the new cassette tape could play lower and richer bass tones than the record. Subwoofers became a common part of most speaker systems.
  
  

Features

• The subwoofer box is made up of several woofers mounted together and encased in a wooden, fiberboard or plastic cabinet. The woofers can be up to 21 inches in diameter, though the most common size for home stereo systems is 15 inches. The dynamics of the cabinet surrounding the woofer unit is designed based on the woofer parameters to increase efficiency and decrease sound distortion.
  
  

Types

• There are two types of subwoofers: active and passive. Active subwoofers are built with amplifiers and equalizers included in the cabinet design; passive subwoofers do not include an amplifier and equalizer. Amplifiers are devices that increase the volume capacity of the subwoofer without compromising much of the sound quality. They are often coupled with equalizers that allow users to manually adjust the output of individual frequencies. Both of these enhancements are used to decrease distortion and create the purest bass sound possible in the subwoofer. Today, most home stereo subwoofers are active subwoofers, though the music recording industry still utilizes passive subwoofers as a tone-producing tool.
  
  

Benefits

• One of the advantages of a subwoofer in a home stereo system is, it decreases the size of the main speakers. Since they do not need to have large woofers to conduct the bass tones, main speakers can be made significantly smaller--which is helpful when the consumer is placing them around her home. The bass sound of a subwoofer is not compromised by medium-size objects in front of it, so it may be placed unobtrusively behind couches, desks and other pieces of furniture, offering quality sound without visually compromising the space.
  
  

Considerations

• Subwoofer boxes that are part of car speaker systems are typically maintained in the trunk or back seat. Bass shakers, an addition to the subwoofer system that heightens that physical sensation of the bass vibration, have become popular among car enthusiasts. These bass shakers produce the rattling sound a car makes when playing music with lots of bass beat, like hip-hop, rap and rock.