A subwoofer is a loudspeaker designed to reproduce low-pitched audio frequencies known as bass and sub-bass, lower in frequency than those which can be (optimally) generated by a woofer. The typical frequency range for a subwoofer is about 20–200 Hz for consumer products, below 100 Hz for professional live sound, and below 80 Hz in THX-certified systems. Thus one or more subwoofers are important for high quality sound reproduction as they are responsible for the lowest two to three octaves of the ten that are audible. This very low-frequency (VLF) range reproduces the natural fundamental tones of the bass drum, electric bass, double bass, grand piano, contrabassoon, tuba, in addition to thunder, gunshots, explosions, etc.
A loudspeaker is an electroacoustic transducer that converts an electrical audio signal into a corresponding sound. A speaker system, also often simply referred to as a speaker or loudspeaker, comprises one or more such speaker drivers, an enclosure, and electrical connections possibly including a crossover network. The speaker driver can be viewed as a linear motor attached to a diaphragm which couples that motor's movement to motion of air, that is, sound. An audio signal, typically from a microphone, recording, or radio broadcast, is amplified electronically to a power level capable of driving that motor in order to reproduce the sound corresponding to the original unamplified electronic signal. This is thus the opposite function to the microphone; indeed the dynamic speaker driver, by far the most common type, is a linear motor in the same basic configuration as the dynamic microphone which uses such a motor in reverse, as a generator.
An audiophile is a person who is enthusiastic about high-fidelity sound reproduction. An audiophile seeks to reproduce recorded music to achieve high sound quality, typically inside closed headphones, in-ear monitors, open headphones in a quiet listening space, or stereo speakers in a room with good acoustics.
A tweeter or treble speaker is a special type of loudspeaker that is designed to produce high audio frequencies, typically deliver high frequencies up to 100 kHz. The name is derived from the high pitched sounds made by some birds (tweets), especially in contrast to the low woofs made by many dogs, after which low-frequency drivers are named (woofers).
A mid-range speaker is a loudspeaker driver that reproduces sound in the frequency range from 250 to 2000 Hz.
Klipsch Audio Technologies is an American loudspeaker company based in Indianapolis, Indiana. Founded in Hope, Arkansas, in 1946 as 'Klipsch and Associates' by Paul W. Klipsch, the company produces loudspeaker drivers and enclosures, as well as complete loudspeakers for high-end, high-fidelity sound systems, public address applications, and personal computers.
MartinLogan (ML) is a Canadian/US company producing conventional subwoofer speakers as well as floor-standing, wall-mounted, and in-wall hybrid speakers using electrostatic loudspeaker and planar magnetic thin film loudspeaker technology.
Magnepan is a private high-end audio loudspeaker manufacturer in White Bear Lake, Minnesota, United States. Their loudspeaker technology was conceived and implemented by engineer Jim Winey in 1969.
Roksan is a British manufacturer of high fidelity audio products for domestic use, based in Rayleigh, Essex. It is best known for its influential and innovative design for hi-fi equipment, and in particular its Xerxes platform for playing LP records.
Infinity Systems is an American manufacturer of loudspeakers founded in Los Angeles in 1968 and headquartered in Stamford, Connecticut. Since 1983, Infinity has been part of Harman International Industries, which became a subsidiary of Samsung Electronics in 2017.
Monsoon is a brand of loudspeakers, originally automotive speaker systems and later computer speakers. Monsoon was originally associated with OEM-sourced automotive audio speaker systems, notably supplied on a number of General Motors products and then later expanded onto other manufacturers such as Volkswagen. The brand name was also licensed to Sonigistix, a Richmond, B.C., Canada company, and applied to their line of computer multimedia speakers.
A rotary woofer is a subwoofer-style loudspeaker which reproduces very low frequency content by using a conventional speaker voice coil's motion to change the pitch of an impeller rotating at a constant speed. The pitch of the fan blades is controlled by the audio signal presented to the voice coil, and is able to swing both positive and negative, with respect to a zero pitch spinning blade position. Since the audio amplifier only changes the pitch of the blades, it takes much less power, per dB of generated acoustic sound level, to drive a rotary woofer than to power a conventional subwoofer, which uses a moving electromagnet placed within the field of a stationary permanent magnet to drive a cone which then displaces air. Rotary woofers excel at producing sounds below 20 Hz, below the normal hearing range; when installed in the wall of a sealed room, they can produce audio frequencies down to 0 Hz, a static pressure differential, by simply compressing the air in the sealed room.
The Air Motion Transformer (AMT) is a type of electroacoustic transducer. Invented by Oskar Heil (1908–1994), it operates on a different transduction principle from other loudspeaker designs, such as moving coil, planar magnetic or electrostatically-driven loudspeakers, and should not be confused with planar or true ribbon loudspeakers. In contrast to a planar ribbon loudspeaker, the diaphragm of the AMT is of pleated shape similar to a bellows. The AMT moves air laterally in a perpendicular motion using a metal-etched folded sheet made of polyethylene terephthalate (PET) film. The circuit path embossed on the PET membrane, acts as the voice coil unit. The diaphragm is then housed between 4 stacks of steel pole-plate pieces positioned at 45° within a high-intensity, quadratic, opposing magnetic field. The air motion transformer with its sheet film equally exposed at 180° behaves as a dipole speaker, exciting front and rear sonic waves simultaneously.
Acoustic suspension is a method of loudspeaker cabinet design and utilisation that uses one or more loudspeaker drivers mounted in a sealed box or cabinet. Acoustic suspension systems reduce bass distortion that can be caused by stiff motor suspensions in conventional loudspeakers.
Lipinski Sound is a professional market and audiophile oriented manufacturer of loudspeakers, subwoofers, powered speaker stands, surround sound systems, power amplifiers, microphones, and microphone preamplifiers.
An electrodynamic speaker driver, often called simply a speaker driver when the type is implicit, is an individual transducer that converts an electrical audio signal to sound waves. While the term is sometimes used interchangeably with the term speaker (loudspeaker), it is usually applied to specialized transducers which reproduce only a portion of the audible frequency range. For high fidelity reproduction of sound, multiple loudspeakers are often mounted in the same enclosure, each reproducing a different part of the audible frequency range. In this case the individual speakers are referred to as drivers and the entire unit is called a loudspeaker. Drivers made for reproducing high audio frequencies are called tweeters, those for middle frequencies are called mid-range drivers, and those for low frequencies are called woofers, while those for very low bass range are subwoofers. Less common types of drivers are supertweeters and rotary woofers.
KEF is a British company specialising in the design and production of a range of high-end audio products, including HiFi speakers, subwoofers, architecture speakers, wireless speakers, and headphones. It was founded in Maidstone, Kent in 1961 by a BBC engineer Raymond Cooke OBE (1925–1995).
Veritone Minimum Phase Speakers, or VMPS, was a loudspeaker manufacturer founded in 1977 by speaker designer Brian Cheney. Many VMPS speakers received favorable reviews from audio critics, such as the RM40, which was awarded Best of CES in the High-End Audio category in 2002. VMPS was in operation for over 35 years, from January 1977 to December 2012, when it closed soon after the death of company owner Brian Cheney on December 7, 2012.
Thomas J. Danley is an American audio engineer, electrical engineer and inventor, the holder of multiple patents for audio transducers, especially high-linearity, high-output professional horn loudspeaker systems. Danley first gained notice in the 1980s with his novel servomotor-driven subwoofer systems used to reproduce very low frequencies in concert tours and theme parks. In 2000 he advanced the implementation of multiple-entry horns in 2000 with several designs led by the SPL-td1, a seven-driver loudspeaker. In 2005, he started a new company, Danley Sound Labs, through which he patented further technologies and produced a wide variety of loudspeaker models based on these technologies.
In a loudspeaker, power compression or thermal compression is a loss of efficiency observed as the voice coil heats up under operation, increasing the DC resistance of the voice coil and decreasing the effective available power of the audio amplifier. A loudspeaker that becomes hot from use may not produce as much sound pressure level as when it is cold. The problem is much greater for hard-driven professional concert systems than it is for loudspeakers in the home, where it is rarely seen. Two main pathways exist to mitigate the problem: to design a way for the voice coil to dissipate more heat during operation, and to design a more efficient transducer that generates less heat for a given sound output level.
