112-559: Celestion is a British designer and exporter of professional loudspeakers . What became Celestion was started in Hampton Wick (suburban London) in 1924. Cyril French and his three brothers had taken over a plating works and established the Electrical Manufacturing and Plating Company. They were listed as "electrical instrument manufacturers". Eric Mackintosh approached Cyril French for assistance with improving
224-408: A crossover network ). The speaker driver is an electroacoustic transducer that converts an electrical audio signal into a corresponding sound . The 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
336-435: A whizzer : a small, light cone attached to the joint between the voice coil and the primary cone. The whizzer cone extends the high-frequency response of the driver and broadens its high-frequency directivity, which would otherwise be greatly narrowed due to the outer diameter cone material failing to keep up with the central voice coil at higher frequencies. The main cone in a whizzer design is manufactured so as to flex more in
448-515: A clothing company in 1970, and the result was now named Celestion Industries, which in turn became Celestion International Ltd. in 1979. In 1992 the loudspeaker part of the business (Celestion International) was sold to Kinergetics Holdings (UK) Ltd., which also bought the company KEF . Today Celestion International and KEF together form Gold Peak Acoustics UK. In 2006 Celestion ceased to manufacture finished professional audio systems and consumer hi-fi / home cinema products, and now focuses on
560-402: A combination of one or more resistors , inductors and capacitors . These components are combined to form a filter network and are most often placed between the full frequency-range power amplifier and the loudspeaker drivers to divide the amplifier's signal into the necessary frequency bands before being delivered to the individual drivers. Passive crossover circuits need no external power beyond
672-808: A complete loudspeaker system to provide performance beyond that constraint. The three most commonly used sound radiation systems are the cone, dome and horn-type drivers. A full- or wide-range driver is a speaker driver designed to be used alone to reproduce an audio channel without the help of other drivers and therefore must cover the audio frequency range required by the application. These drivers are small, typically 3 to 8 inches (7.6 to 20.3 cm) in diameter to permit reasonable high-frequency response, and carefully designed to give low-distortion output at low frequencies, though with reduced maximum output level. Full-range drivers are found, for instance, in public address systems, in televisions, small radios, intercoms, and some computer speakers . In hi-fi speaker systems,
784-512: A cone-shaped bass unit of PVC with integrated dustcap. Both speaker drivers designed with the help of laser interferometry . Afterwards followed the model SL600 , which won worldwide awards in the audiophile hi-fi scene. Instead of wood for the loudspeaker enclosure a rigid honeycomb alloy called Aerolam was chosen, a material previously used only in the aerospace industry. Then followed versions with aluminium dome tweeter, designated as SL6s in standard cabinets ( MDF and wood veneer ), and
896-426: A crossover knob and a phase switch). These variants are known as active or powered subwoofers. In contrast, passive subwoofers require external amplification. In typical installations, subwoofers are physically separated from the rest of the speaker cabinets. Because of propagation delay and positioning, their output may be out of phase with the rest of the sound. Consequently, a subwoofer's power amp often has
1008-402: A detailed mid and bass range. Their tweeters produced very clear voices, good especially for vocal and classical music recordings. But the copper dome versions were also known for a somewhat "depressed" sounding high-frequency range, due to the relatively heavy material. Later versions used an aluminium diaphragm dome. This lighter and more efficient driver provided an output now more balanced with
1120-426: A driver; each implementation has advantages and disadvantages. Polyester foam, for example, is lightweight and economical, though usually leaks air to some degree and is degraded by time, exposure to ozone, UV light, humidity and elevated temperatures, limiting useful life before failure. The wire in a voice coil is usually made of copper , though aluminum —and, rarely, silver —may be used. The advantage of aluminum
1232-421: A dual role, acting also as a choke coil , filtering the power supply of the amplifier that the loudspeaker was connected to. AC ripple in the current was attenuated by the action of passing through the choke coil. However, AC line frequencies tended to modulate the audio signal going to the voice coil and added to the audible hum. In 1930 Jensen introduced the first commercial fixed-magnet loudspeaker; however,
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#17327979392291344-406: A dynamic loudspeaker, uses a lightweight diaphragm , or cone , connected to a rigid basket , or frame , via a flexible suspension, commonly called a spider , that constrains a voice coil to move axially through a cylindrical magnetic gap. A protective dust cap glued in the cone's center prevents dust, most importantly ferromagnetic debris, from entering the gap. When an electrical signal
1456-463: A high-frequency horn that sent sound through a hole in the pole piece of a 15-inch woofer for near-point-source performance. Altec's "Voice of the Theatre" loudspeaker system was first sold in 1945, offering better coherence and clarity at the high output levels necessary in movie theaters. The Academy of Motion Picture Arts and Sciences immediately began testing its sonic characteristics; they made it
1568-405: A larger magnet for equivalent performance. Electromagnets were often used in musical instrument amplifiers cabinets well into the 1950s; there were economic savings in those using tube amplifiers as the field coil could, and usually did, do double duty as a power supply choke. Very few manufacturers still produce electrodynamic loudspeakers with electrically powered field coils , as was common in
1680-511: A listening test is done in such a way that the listener who is assessing the sound quality of a component or recording can see the components that are being used for the test (e.g., the same musical piece listened to through a tube power amplifier and a solid-state amplifier), then it is possible that the listener's pre-existing biases towards or against certain components or brands could affect their judgment. To respond to this issue, researchers began to use blind tests , in which listeners cannot see
1792-550: A new loudspeaker he had already filed a patent for (British Patent No. 230,552 on 15 December 1923, issued 16 March 1925). The BBC had started their programme in November 1922 and was building up new senders, public interest in radio broadcasting grew rapidly. But listeners still needed to connect either earphones or gramophone horns to the first radio receivers . Installing a loudspeaker sensitive enough in decorative cabinets quickly made these sought-after pieces of furniture in
1904-534: A partial solution to the problem of reproducing the sound of live orchestral performers by creating separation among instruments, the illusion of space, and a phantom central channel. An attempt to enhance reverberation was tried in the 1970s through quadraphonic sound . Consumers did not want to pay the additional costs and space required for the marginal improvements in realism. With the rise in popularity of home theater , however, multi-channel playback systems became popular, and many consumers were willing to tolerate
2016-419: A phase-delay adjustment which may be used improve performance of the system as a whole. Subwoofers are widely used in large concert and mid-sized venue sound reinforcement systems. Subwoofer cabinets are often built with a bass reflex port, a design feature which if properly engineered improves bass performance and increases efficiency. A woofer is a driver that reproduces low frequencies. The driver works with
2128-623: A power amplifier in one box is called an integrated amplifier ; with a tuner added, it is a receiver . A monophonic power amplifier is called a monoblock and is often used for powering a subwoofer . Other modules in the system may include components like cartridges , tonearms , hi-fi turntables , digital media players , DVD players that play a wide variety of discs including CDs , CD recorders , MiniDisc recorders, hi-fi videocassette recorders (VCRs) and reel-to-reel tape recorders . Signal modification equipment can include equalizers and noise-reduction systems . This modularity allows
2240-412: 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 . The dynamic speaker
2352-414: A separate box, necessary to accommodate the size of the components used. Passive crossovers may be simple for low-order filtering, or complex to allow steep slopes such as 18 or 24 dB per octave. Passive crossovers can also be designed to compensate for undesired characteristics of driver, horn, or enclosure resonances, and can be tricky to implement, due to component interaction. Passive crossovers, like
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#17327979392292464-483: A single driver enclosed in a suitable enclosure. Since sound in this frequency range can easily bend around corners by diffraction , the speaker aperture does not have to face the audience, and subwoofers can be mounted in the bottom of the enclosure, facing the floor. This is eased by the limitations of human hearing at low frequencies; Such sounds cannot be located in space, due to their large wavelengths compared to higher frequencies which produce differential effects in
2576-408: A single piece, called the poleplate or yoke. The size and type of magnet and details of the magnetic circuit differ, depending on design goals. For instance, the shape of the pole piece affects the magnetic interaction between the voice coil and the magnetic field, and is sometimes used to modify a driver's behavior. A shorting ring , or Faraday loop , may be included as a thin copper cap fitted over
2688-471: A solid-state amplifier, the Quad 405, in 1978 after seeing the results from blind tests, but came to realize months later that "the magic was gone" until he replaced it with a tube amp. Robert Harley of The Absolute Sound wrote, in 2008, that: "...blind listening tests fundamentally distort the listening process and are worthless in determining the audibility of a certain phenomenon." Doug Schneider, editor of
2800-481: A stereo (stereophonic phonograph). In the world of the audiophile, however, the concept of high fidelity continued to refer to the goal of highly accurate sound reproduction and to the technological resources available for approaching that goal. This period is regarded as the "Golden Age of Hi-Fi", when vacuum tube equipment manufacturers of the time produced many models considered superior by modern audiophiles, and just before solid state ( transistorized ) equipment
2912-411: A system using compressed air as an amplifying mechanism for his early cylinder phonographs, but he ultimately settled for the familiar metal horn driven by a membrane attached to the stylus. In 1898, Horace Short patented a design for a loudspeaker driven by compressed air; he then sold the rights to Charles Parsons , who was issued several additional British patents before 1910. A few companies, including
3024-410: A transformer, the matched units were staggered. This eliminated the tendency to "boom" greatly, because the bass could be better suppressed. The latter had large and small speakers built in and a transformer. The two units were so coupled that the treble was accepted by the treble unit and the bass by the bass unit, being essentially a two-way, crossover-less splitting system. In 1932 Celestion brought
3136-623: A variation of the aluminium tweeter with an updated faceplate. The Celestion Kingston was introduced in 1995 as an evolution of the SL family. The innovative speaker case is made from Alphacrystal , a stone/resin mould. It tapers to the rear in a way that there is no traditional back panel anymore. In 1989 the Celestion 3 with metal dome tweeter was introduced. It set new performance standards for low-cost quality hi-fi loudspeakers, highly acclaimed by both public and critics. The later 3 Mark II model
3248-445: A wide range of frequencies with even coverage, most loudspeaker systems employ more than one driver, particularly for higher sound pressure level (SPL) or maximum accuracy. Individual drivers are used to reproduce different frequency ranges. The drivers are named subwoofers (for very low frequencies); woofers (low frequencies); mid-range speakers (middle frequencies); tweeters (high frequencies); and sometimes supertweeters , for
3360-549: Is transparent , a properly conducted double-blind test can prove that a method is not transparent. Blind tests are sometimes used as part of attempts to ascertain whether certain audio components (such as expensive, exotic cables) have any subjectively perceivable effect on sound quality. Data gleaned from these blind tests is not accepted by some audiophile magazines such as Stereophile and The Absolute Sound in their evaluations of audio equipment. John Atkinson , current editor of Stereophile , stated that he once purchased
3472-468: Is 20 Hz to 20,000 Hz. Most adults can't hear higher than 15,000 Hz. CDs are capable of reproducing frequencies as low as 0 Hz and as high as 22,050 Hz, making them adequate for reproducing the frequency range that most humans can hear. The equipment must also provide no noticeable distortion of the signal or emphasis or de-emphasis of any frequency in this frequency range. Integrated , mini , or lifestyle systems (also known by
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3584-478: Is a low priority. A subwoofer is a woofer driver used only for the lowest-pitched part of the audio spectrum: typically below 200 Hz for consumer systems, below 100 Hz for professional live sound, and below 80 Hz in THX -approved systems. Because the intended range of frequencies is limited, subwoofer system design is usually simpler in many respects than for conventional loudspeakers, often consisting of
3696-985: Is a small amount of passive electronics called a crossover network which helps direct components of the electronic signal to the speaker drivers best capable of reproducing those frequencies. In a so-called powered speaker system, the power amplifier actually feeding the speaker drivers is built into the enclosure itself; these have become more and more common especially as computer speakers. Smaller speakers are found in devices such as radios , televisions , portable audio players , personal computers ( computer speakers ), headphones , and earphones . Larger, louder speaker systems are used for home hi-fi systems ( stereos ), electronic musical instruments , sound reinforcement in theaters and concert halls, and in public address systems . The term loudspeaker may refer to individual transducers (also known as drivers ) or to complete speaker systems consisting of an enclosure and one or more drivers. To adequately and accurately reproduce
3808-416: Is applied to the voice coil, a magnetic field is created by the electric current in the voice coil, making it a variable electromagnet. The coil and the driver's magnetic system interact in a manner similar to a solenoid , generating a mechanical force that moves the coil (and thus, the attached cone). Application of alternating current moves the cone back and forth, accelerating and reproducing sound under
3920-551: Is designed to be rigid, preventing deformation that could change critical alignments with the magnet gap, perhaps allowing the voice coil to rub against the magnet around the gap. Chassis are typically cast from aluminum alloy, in heavier magnet-structure speakers; or stamped from thin sheet steel in lighter-structure drivers. Other materials such as molded plastic and damped plastic compound baskets are becoming common, especially for inexpensive, low-mass drivers. A metallic chassis can play an important role in conducting heat away from
4032-404: Is its light weight, which reduces the moving mass compared to copper. This raises the resonant frequency of the speaker and increases its efficiency. A disadvantage of aluminum is that it is not easily soldered, and so connections must be robustly crimped together and sealed. Voice-coil wire cross sections can be circular, rectangular, or hexagonal, giving varying amounts of wire volume coverage in
4144-458: Is the music server consisting of one or more computer hard drives that hold music in the form of computer files . When the music is stored in an audio file format that is lossless such as FLAC , Monkey's Audio or WMA Lossless , the computer playback of recorded audio can serve as an audiophile-quality source for a hi-fi system. There is now a push from certain streaming services to offer hi-fi services. Streaming services typically have
4256-476: Is the high-quality reproduction of sound . It is popular with audiophiles and home audio enthusiasts. Ideally, high-fidelity equipment has inaudible noise and distortion , and a flat (neutral, uncolored) frequency response within the human hearing range . High fidelity contrasts with the lower-quality " lo-fi " sound produced by inexpensive audio equipment, AM radio , or the inferior quality of sound reproduction that can be heard in recordings made until
4368-437: Is usually conically shaped for sturdiness) in contact with air, thus creating sound waves . In addition to dynamic speakers, several other technologies are possible for creating sound from an electrical signal, a few of which are in commercial use. In order for a speaker to efficiently produce sound, especially at lower frequencies, the speaker driver must be baffled so that the sound emanating from its rear does not cancel out
4480-484: Is well damped to reduce vibrations continuing after the signal has stopped with little or no audible ringing due to its resonance frequency as determined by its usage. In practice, all three of these criteria cannot be met simultaneously using existing materials; thus, driver design involves trade-offs . For example, paper is light and typically well-damped, but is not stiff; metal may be stiff and light, but it usually has poor damping; plastic can be light, but typically,
4592-411: The C range of loadspeakers were supplemented by the new models D10, D12 and D50. Technological improvements meant Celestion had to stay up to date. The first electrical disc-playing machines appeared on the market in the late 1920s. These electric " phonographs " (since the 1940s known as record players, or nowadays as turntables) became more widespread, later to be combined with a radio receiver. Also in
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4704-602: The Celestion Radio Company and Celestion Ltd. were formed, which grew and became highly successful quickly. The new models C10, C12, C14 and C24 were brought to market, especially the C10 and C12 were highly praised. For many years Celestion advertising would carry the phrase "The very Soul of Music". In 1929 Celestion Ltd. moved across the Thames to Kingston upon Thames , now listed as "Gramophone Works". In 1931
4816-704: The Ppm Permanent Magnet Moving Coil Speaker to market. The business was hit hard by the Great Depression , like so many. Furthermore, in 1934 the British Rola Company , a dependance of the U.S. Rola Company of Cleveland, Ohio, opened in London. Rola being another loudspeaker manufacturer with similar products, the two companies began competing for home and export markets. In 1935 Cyril French resigned from
4928-639: The SL6si with an improved audio crossover and woofer surround. Aluminium-domed models using the Aerolam cabinet were the models SL700 , and SL700SE with dual inputs. Another of the copper-domed versions, with Aerolam cabinet, dual inputs and improved crossover elements, was marketed as the SL600si . The speakers of the SL model range were generally well regarded for their natural sound and wide sound dispersion, and
5040-546: The SR (Sound Reinforcement) loudspeaker series with integral aluminium dome followed. A number of companies use Celestion speakers, including Orange Music Electronic Company , Fender Musical Instrument Corporation , Vox , and Marshall Amps . In June 2019, Celestion selected Sensey Electronics as its distribution partner in Mexico, to represent its entire range of pro audio and MI products. In September 2019, Celestion announced
5152-526: The Victor Talking Machine Company and Pathé , produced record players using compressed-air loudspeakers. Compressed-air designs are significantly limited by their poor sound quality and their inability to reproduce sound at low volume. Variants of the design were used for public address applications, and more recently, other variations have been used to test space-equipment resistance to the very loud sound and vibration levels that
5264-506: The audible frequency range. The smaller drivers capable of reproducing the highest audio frequencies are called tweeters , those for middle frequencies are called mid-range drivers and those for low frequencies are called woofers . Sometimes the reproduction of the very lowest frequencies (20–~50 Hz ) is augmented by a so-called subwoofer often in its own (large) enclosure. In a two-way or three-way speaker system (one with drivers covering two or three different frequency ranges) there
5376-639: The film house industry standard in 1955. In 1954, Edgar Villchur developed the acoustic suspension principle of loudspeaker design. This allowed for better bass response than previously obtainable from drivers mounted in larger cabinets. He and his partner Henry Kloss formed the Acoustic Research company to manufacture and market speaker systems using this principle. Subsequently, continuous developments in enclosure design and materials led to significant audible improvements. The most notable improvements to date in modern dynamic drivers, and
5488-418: The mid frequencies (between the woofer and tweeter). Mid-range driver diaphragms can be made of paper or composite materials and can be direct radiation drivers (rather like smaller woofers) or they can be compression drivers (rather like some tweeter designs). If the mid-range driver is a direct radiator, it can be mounted on the front baffle of a loudspeaker enclosure, or, if a compression driver, mounted at
5600-423: The roaring twenties . French and Mackintosh perfected the design, the modified French/Mackintosh model used a clamped edge, its conical paper diaphragm was strengthened with strips of Chinese bamboo (British Patent No. 245,704, filed 24 October 1925, issued 14 January 1926). Cyril French became the driving force of the endeavour to start manufacturing it in his company. The first housed loudspeaker, Celestion ,
5712-528: The spider , which connects the diaphragm or voice coil to the lower frame and provides the majority of the restoring force, and the surround , which helps center the coil/cone assembly and allows free pistonic motion aligned with the magnetic gap. The spider is usually made of a corrugated fabric disk, impregnated with a stiffening resin. The name comes from the shape of early suspensions, which were two concentric rings of Bakelite material, joined by six or eight curved legs . Variations of this topology included
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#17327979392295824-420: The (intended) sound from the front; this generally takes the form of a speaker enclosure or speaker cabinet , an often rectangular box made of wood, but sometimes metal or plastic. The enclosure's design plays an important acoustic role thus determining the resulting sound quality. Most high fidelity speaker systems (picture at right) include two or more sorts of speaker drivers, each specialized in one part of
5936-477: The 1930s receivers became more sophisticated and smaller, loudspeakers now were being built into the receiver cabinet itself, thus a separate unit was not necessary anymore. Many ingenious ideas were incorporated in new designs in order to raise the quality of sound reproduction, such as the Celestion Reetone and Reetone Dual matched speaker units. The former incorporated two equal-sized speakers with
6048-471: The 1930s, Avery Fisher , an amateur violinist, began experimenting with audio design and acoustics . He wanted to make a radio that would sound like he was listening to a live orchestra and achieve high fidelity to the original sound. After World War II , Harry F. Olson conducted an experiment whereby test subjects listened to a live orchestra through a hidden variable acoustic filter. The results proved that listeners preferred high-fidelity reproduction, once
6160-462: The 1970s and 1980s preferred to buy each component separately. That way, they could choose models of each component with the specifications that they desired. In the 1980s, several audiophile magazines became available, offering reviews of components and articles on how to choose and test speakers, amplifiers, and other components. Listening tests are used by hi-fi manufacturers, audiophile magazines, and audio engineering researchers and scientists. If
6272-547: The 1970s was the integrated music centre —which combined a phonograph turntable, AM-FM radio tuner, tape player, preamplifier, and power amplifier in one package, often sold with its own separate, detachable or integrated speakers. These systems advertised their simplicity. The consumer did not have to select and assemble individual components or be familiar with impedance and power ratings. Purists generally avoid referring to these systems as high fidelity, though some are capable of very good quality sound reproduction. Audiophiles in
6384-411: The addition of a felt disc to provide a barrier to particles that might otherwise cause the voice coil to rub. The cone surround can be rubber or polyester foam , treated paper or a ring of corrugated, resin-coated fabric; it is attached to both the outer cone circumference and to the upper frame. These diverse surround materials, their shape and treatment can dramatically affect the acoustic output of
6496-406: The advent of integrated multi-speaker console systems in the 1950s, hi-fi became a generic term for home sound equipment, to some extent displacing phonograph and record player . In the late 1950s and early 1960s, the development of stereophonic equipment and recordings led to the next wave of home-audio improvement, and in common parlance stereo displaced hi-fi . Records were now played on
6608-542: The appropriate driver. A loudspeaker system with n separate frequency bands is described as n-way speakers : a two-way system will have a woofer and a tweeter; a three-way system employs a woofer, a mid-range, and a tweeter. Loudspeaker drivers of the type pictured are termed dynamic (short for electrodynamic) to distinguish them from other sorts including moving iron speakers , and speakers using piezoelectric or electrostatic systems. Johann Philipp Reis installed an electric loudspeaker in his telephone in 1861; it
6720-416: The audio signal itself, but have some disadvantages: they may require larger inductors and capacitors due to power handling requirements. Unlike active crossovers which include a built-in amplifier, passive crossovers have an inherent attenuation within the passband , typically leading to a reduction in damping factor before the voice coil. An active crossover is an electronic filter circuit that divides
6832-481: The board of Celestion Ltd, Eric Mackintosh also left in the early 1930s. With the 1940s wartime restrictions forced Celestion and the British Rola to produce loudspeakers to the same specification, the utility "W" type. Micro Precision Products , later a camera maker, was formed as a subsidiary during the war. British Rola bought Celestion in 1947 and moved production to Thames Ditton a year later. The name of
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#17327979392296944-449: The characteristics of the speaker enclosure to produce suitable low frequencies. Some loudspeaker systems use a woofer for the lowest frequencies, sometimes well enough that a subwoofer is not needed. Additionally, some loudspeakers use the woofer to handle middle frequencies, eliminating the mid-range driver. A mid-range speaker is a loudspeaker driver that reproduces a band of frequencies generally between 1–6 kHz, otherwise known as
7056-467: The company now changed to Rola Celestion , with its products sold under the brand name Celestion . The company continued making radio, " high fidelity ", and television speakers in the postwar years. In 1949, Rola Celestion was bought by Truvox , a public address system manufacturer. In 1968 Celestion started production in Ipswich , Suffolk, moving all manufacturing there by 1975. The firm merged with
7168-455: The components being tested. A commonly used variant of this test is the ABX test . A subject is presented with two known samples (sample A , the reference, and sample B , an alternative), and one unknown sample X, for three samples total. X is randomly selected from A and B , and the subject identifies X as being either A or B . Although there is no way to prove that a certain methodology
7280-486: The control of the applied electrical signal coming from the amplifier. The following is a description of the individual components of this type of loudspeaker. The diaphragm is usually manufactured with a cone- or dome-shaped profile. A variety of different materials may be used, but the most common are paper, plastic, and metal. The ideal material is rigid, to prevent uncontrolled cone motions, has low mass to minimize starting force requirements and energy storage issues and
7392-413: The crossover is an assembly of filters that separate the input signal into different frequency bands according to the requirements of each driver. Hence the drivers receive power only in the sound frequency range they were designed for, thereby reducing distortion in the drivers and interference between them. Crossovers can be passive or active . A passive crossover is an electronic circuit that uses
7504-546: The design and manufacture of lead guitar, bass guitar, professional audio and sound reinforcement speakers. Somewhere around 1969 the Celestion Ditton range of consumer stereo teak veneered floor speakers was unleashed on the British public. The range would go on to include smaller bookshelf models, but initially the lowest model was the very popular Ditton 15, to be renamed the 15XR (see the catalogue from 1978), and
7616-746: The driver units that they feed, have power handling limits, have insertion losses , and change the load seen by the amplifier. The changes are matters of concern for many in the hi-fi world. When high output levels are required, active crossovers may be preferable. Active crossovers may be simple circuits that emulate the response of a passive network or may be more complex, allowing extensive audio adjustments. Some active crossovers, usually digital loudspeaker management systems, may include electronics and controls for precise alignment of phase and time between frequency bands, equalization, dynamic range compression and limiting . Most loudspeaker systems consist of drivers mounted in an enclosure, or cabinet. The role of
7728-454: The drivers by moving one or more driver mounting locations forward or back so that the acoustic center of each driver is in the same vertical plane. This may also involve tilting the driver back, providing a separate enclosure mounting for each driver, or using electronic techniques to achieve the same effect. These attempts have resulted in some unusual cabinet designs. High fidelity High fidelity (often shortened to Hi-Fi or HiFi )
7840-487: The drivers mounted in holes in it. However, in this approach, sound frequencies with a wavelength longer than the baffle dimensions are canceled out because the antiphase radiation from the rear of the cone interferes with the radiation from the front. With an infinitely large panel, this interference could be entirely prevented. A sufficiently large sealed box can approach this behavior. Since panels of infinite dimensions are impossible, most enclosures function by containing
7952-589: The earliest designs. Speaker system design involves subjective perceptions of timbre and sound quality, measurements and experiments. Adjusting a design to improve performance is done using a combination of magnetic, acoustic, mechanical, electrical, and materials science theory, and tracked with high-precision measurements and the observations of experienced listeners. A few of the issues speaker and driver designers must confront are distortion, acoustic lobing , phase effects, off-axis response, and crossover artifacts. Designers can use an anechoic chamber to ensure
8064-501: The ears due to shadowing by the head, and diffraction around it, both of which we rely upon for localization clues. To accurately reproduce very low bass notes, subwoofer systems must be solidly constructed and properly braced to avoid unwanted sounds from cabinet vibrations. As a result, good subwoofers are typically quite heavy. Many subwoofer systems include integrated power amplifiers and electronic subsonic -filters, with additional controls relevant to low-frequency reproduction (e.g.
8176-422: The enclosure is to prevent sound waves emanating from the back of a driver from interfering destructively with those from the front. The sound waves emitted from the back are 180° out of phase with those emitted forward, so without an enclosure they typically cause cancellations which significantly degrade the level and quality of sound at low frequencies. The simplest driver mount is a flat panel ( baffle ) with
8288-649: The enthusiast to spend as little or as much as they want on a component to suit their specific needs, achieve a desired sound, and add components as desired. Also, failure of any component of an integrated system can render it unusable, while the unaffected components of a modular system may continue to function. A modular system introduces the complexity of cabling multiple components and often having different remote controls for each unit. Some modern hi-fi equipment can be digitally connected using fiber optic TOSLINK cables, USB ports (including one to play digital audio files), or Wi-Fi support. Another modern component
8400-429: The first film industry-standard loudspeaker system, "The Shearer Horn System for Theatres", a two-way system, was introduced by Metro-Goldwyn-Mayer . It used four 15" low-frequency drivers, a crossover network set for 375 Hz, and a single multi-cellular horn with two compression drivers providing the high frequencies. John Kenneth Hilliard , James Bullough Lansing , and Douglas Shearer all played roles in creating
8512-433: The highest audible frequencies and beyond. The terms for different speaker drivers differ, depending on the application. In two-way systems there is no mid-range driver, so the task of reproducing the mid-range sounds is divided between the woofer and tweeter. When multiple drivers are used in a system, a filter network, called an audio crossover , separates the incoming signal into different frequency ranges and routes them to
8624-419: The large, heavy iron magnets of the day were impractical and field-coil speakers remained predominant until the widespread availability of lightweight alnico magnets after World War II. In the 1930s, loudspeaker manufacturers began to combine two and three drivers or sets of drivers each optimized for a different frequency range in order to improve frequency response and increase sound pressure level. In 1937,
8736-969: The late 1940s. Bell Laboratories began experimenting with various recording techniques in the early 1930s. Performances by Leopold Stokowski and the Philadelphia Orchestra were recorded in 1931 and 1932 using telephone lines between the Academy of Music in Philadelphia and the Bell labs in New Jersey. Some multitrack recordings were made on optical sound film, which led to new advances used primarily by MGM (as early as 1937) and Twentieth Century Fox Film Corporation (as early as 1941). RCA Victor began recording performances by several orchestras using optical sound around 1941, resulting in higher-fidelity masters for 78-rpm discs . During
8848-541: The launch of the F12-X200 guitar loudspeaker, the first speaker designer specifically for use with profiling amps, modeling software, impulse responses and other technologies which are designed for emulating the tones from guitar amps and speaker cabinets. Loudspeaker A loudspeaker (commonly referred to as a speaker or, more fully, a speaker system ) is a combination of one or more speaker drivers , an enclosure , and electrical connections (possibly including
8960-510: The launching of rockets produces. The first experimental moving-coil (also called dynamic ) loudspeaker was invented by Oliver Lodge in 1898. The first practical moving-coil loudspeakers were manufactured by Danish engineer Peter L. Jensen and Edwin Pridham in 1915, in Napa, California . Like previous loudspeakers these used horns to amplify the sound produced by a small diaphragm. Jensen
9072-415: The loudspeaker diaphragm—again resulting in degradation of sound quality. This can be reduced by internal absorption using absorptive materials such as glass wool , wool, or synthetic fiber batting, within the enclosure. The internal shape of the enclosure can also be designed to reduce this by reflecting sounds away from the loudspeaker diaphragm, where they may then be absorbed. Other enclosure types alter
9184-454: The loudspeakers that employ them, are improvements in cone materials, the introduction of higher-temperature adhesives, improved permanent magnet materials, improved measurement techniques, computer-aided design , and finite element analysis. At low frequencies, Thiele/Small parameters electrical network theory has been used to optimize bass driver and enclosure synergy since the early 1970s. The most common type of driver, commonly called
9296-420: The magnetic gap space. The coil is oriented co-axially inside the gap; it moves back and forth within a small circular volume (a hole, slot, or groove) in the magnetic structure. The gap establishes a concentrated magnetic field between the two poles of a permanent magnet; the outside ring of the gap is one pole, and the center post (called the pole piece) is the other. The pole piece and backplate are often made as
9408-434: The manufacturer to allow piecemeal repairs. Although some high-end audio manufacturers do produce integrated systems, such products are generally disparaged by audiophiles , who prefer to build a system from separates (or components ), often with each item from a different manufacturer specialising in a particular component. This provides the most flexibility for piece-by-piece upgrades and repairs. A preamplifier and
9520-625: The mid-range part the woofer presented, which in the first version had lacked of bass to better connect to the tweeter frequencies. In 1986 Celestion introduced the System 6000 , a double-dipole subwoofer system with active audio crossover to complement and enhance the SL series. In 1992 the Model 100 , a final variation of the SL design, came to market. It featured a conventional, but highly refined MDF / wood veneer cabinet, dual inputs, updated mounted plates, improved audio crossover and woofer design, and
9632-451: The minimum number of amplifier channels. Some loudspeaker designs use a combination of passive and active crossover filtering, such as a passive crossover between the mid- and high-frequency drivers and an active crossover for the low-frequency driver. Passive crossovers are commonly installed inside speaker boxes and are by far the most common type of crossover for home and low-power use. In car audio systems, passive crossovers may be in
9744-433: The noise and distortion introduced by early sound equipment was removed. Beginning in 1948, several innovations created the conditions that made major improvements in home audio quality possible: In the 1950s, audio manufacturers employed the phrase high fidelity as a marketing term to describe records and equipment intended to provide faithful sound reproduction. Many consumers found the difference in quality compared to
9856-488: The older terms music centre or midi system ) contain one or more sources such as a CD player , a tuner , or a cassette tape deck together with a preamplifier and a power amplifier in one box. A limitation of an "integrated" system is that failure of any one component can possibly lead to the need to replace the entire unit, as components are not readily swapped in or out of a system merely by plugging and unplugging cables, and may not even have been made available by
9968-673: The online Soundstage network, argued the opposite in 2009. He stated: "Blind tests are at the core of the decades' worth of research into loudspeaker design done at Canada's National Research Council (NRC). The NRC researchers knew that for their result to be credible within the scientific community and to have the most meaningful results, they had to eliminate bias, and blind testing was the only way to do so." Many Canadian companies such as Axiom, Energy, Mirage, Paradigm, PSB, and Revel use blind testing extensively in designing their loudspeakers. Audio professional Dr. Sean Olive of Harman International shares this view. Stereophonic sound provided
10080-617: The outer diameter than in the center. The result is that the main cone delivers low frequencies and the whizzer cone contributes most of the higher frequencies. Since the whizzer cone is smaller than the main diaphragm, output dispersion at high frequencies is improved relative to an equivalent single larger diaphragm. Limited-range drivers, also used alone, are typically found in computers, toys, and clock radios . These drivers are less elaborate and less expensive than wide-range drivers, and they may be severely compromised to fit into very small mounting locations. In these applications, sound quality
10192-487: The output power of some designs has been increased to levels useful for professional sound reinforcement, and their output pattern is wide in the horizontal plane, a pattern that has convenient applications in concert sound. A coaxial driver is a loudspeaker driver with two or more combined concentric drivers. Coaxial drivers have been produced by Altec , Tannoy , Pioneer , KEF , SEAS, B&C Speakers, BMS, Cabasse and Genelec . Used in multi-driver speaker systems ,
10304-429: The patent by Rice and Kellogg is the adjustment of mechanical parameters to provide a reasonably flat frequency response . These first loudspeakers used electromagnets , because large, powerful permanent magnets were generally not available at a reasonable price. The coil of an electromagnet, called a field coil, was energized by a current through a second pair of connections to the driver. This winding usually served
10416-453: The pole tip or as a heavy ring situated within the magnet-pole cavity. The benefits of this complication is reduced impedance at high frequencies, providing extended treble output, reduced harmonic distortion, and a reduction in the inductance modulation that typically accompanies large voice coil excursions. On the other hand, the copper cap requires a wider voice-coil gap, with increased magnetic reluctance; this reduces available flux, requiring
10528-449: The rear radiation from the moving diaphragm. A sealed enclosure prevents transmission of the sound emitted from the rear of the loudspeaker by confining the sound in a rigid and airtight box. Techniques used to reduce the transmission of sound through the walls of the cabinet include thicker cabinet walls, internal bracing and lossy wall material. However, a rigid enclosure reflects sound internally, which can then be transmitted back through
10640-418: The rear sound radiation so it can add constructively to the output from the front of the cone. Designs that do this (including bass reflex , passive radiator , transmission line , etc.) are often used to extend the effective low-frequency response and increase the low-frequency output of the driver. To make the transition between drivers as seamless as possible, system designers have attempted to time align
10752-433: The signal into individual frequency bands before power amplification, thus requiring at least one power amplifier for each band. Passive filtering may also be used in this way before power amplification, but it is an uncommon solution, being less flexible than active filtering. Any technique that uses crossover filtering followed by amplification is commonly known as bi-amping, tri-amping, quad-amping, and so on, depending on
10864-506: The six to eight channels required in a home theater. In addition to spatial realism, the playback of music must be subjectively free from noise, such as hiss or hum, to achieve realism. The compact disc (CD) provides about 90 decibels of dynamic range , which exceeds the 80 dB dynamic range of music as normally perceived in a concert hall. Audio equipment must be able to reproduce frequencies high enough and low enough to be realistic. The human hearing range, for healthy young persons,
10976-496: The speaker can be measured independently of room effects, or any of several electronic techniques that, to some extent, substitute for such chambers. Some developers eschew anechoic chambers in favor of specific standardized room setups intended to simulate real-life listening conditions. Individual electrodynamic drivers provide their best performance within a limited frequency range. Multiple drivers (e.g. subwoofers, woofers, mid-range drivers, and tweeters) are generally combined into
11088-435: The stiffer it is made, the poorer the damping. As a result, many cones are made of some sort of composite material. For example, a cone might be made of cellulose paper, into which some carbon fiber , Kevlar , glass , hemp or bamboo fibers have been added; or it might use a honeycomb sandwich construction; or a coating might be applied to it so as to provide additional stiffening or damping. The chassis, frame, or basket,
11200-436: The system. At the 1939 New York World's Fair , a very large two-way public address system was mounted on a tower at Flushing Meadows . The eight 27" low-frequency drivers were designed by Rudy Bozak in his role as chief engineer for Cinaudagraph. High-frequency drivers were likely made by Western Electric . Altec Lansing introduced the 604 , which became their most famous coaxial Duplex driver, in 1943. It incorporated
11312-464: The then-standard AM radios and 78-rpm records readily apparent and bought high-fidelity phonographs and 33⅓ LPs such as RCA 's New Orthophonics and London's FFRR (Full Frequency Range Recording, a UK Decca system). Audiophiles focused on technical characteristics and bought individual components, such as separate turntables, radio tuners, preamplifiers , power amplifiers and loudspeakers. Some enthusiasts even assembled their loudspeaker systems, with
11424-534: The throat of a horn for added output level and control of radiation pattern. A tweeter is a high-frequency driver that reproduces the highest frequencies in a speaker system. A major problem in tweeter design is achieving wide angular sound coverage (off-axis response), since high-frequency sound tends to leave the speaker in narrow beams. Soft-dome tweeters are widely found in home stereo systems, and horn-loaded compression drivers are common in professional sound reinforcement. Ribbon tweeters have gained popularity as
11536-628: The time, helped to define the electric guitar sound. It was rapidly adopted by pioneers of rock & roll and popular music throughout the late 1950s and early 1960s. In 1984 the Sidewinder range of guitar speakers were unveiled. These were endowed with a special edgewound aluminium voice coil – a process developed to maximise the ratio of motor strength to mass which resulted in very high efficiency designs. In 1986 Celestion introduced its B15 and B18 range of double suspension public address systems , with power ratings up to 1,000 Watts. In 1987
11648-442: The top of the range was the formidable and always rare Ditton 66. Most models, including these two, featured ported cabinets and passive full size Auxiliary Bass Radiators (ABRs) which gave out controlled low frequencies. The 15 had 8" drivers (1 regular and 1 ABR), and the 66 had 12" similarly. In 1981 Celestion built the hi-fi box model SL6 , a compact two-way loudspeaker with a single-piece metal dome tweeter made of copper and
11760-454: The use of wide-range drivers can avoid undesirable interactions between multiple drivers caused by non-coincident driver location or crossover network issues but also may limit frequency response and output abilities (most especially at low frequencies). Hi-fi speaker systems built with wide-range drivers may require large, elaborate or, expensive enclosures to approach optimum performance. Full-range drivers often employ an additional cone called
11872-405: The voice coil; heating during operation changes resistance, causes physical dimensional changes, and if extreme, broils the varnish on the voice coil; it may even demagnetize permanent magnets. The suspension system keeps the coil centered in the gap and provides a restoring (centering) force that returns the cone to a neutral position after moving. A typical suspension system consists of two parts:
11984-644: Was awarded the " 1994/95 European Loudspeaker of the Year " by the European Imaging and Sound Association . According to the company the Celestion Blue , the model G12 T530 driver, was the world's first dedicated guitar loudspeaker. The 1950s emergence of louder guitar amplifiers created a need for a rugged, reliable loudspeaker. Celestion responded by modifying their standard "G12" radio speaker. The tonal character, combined with valve amp circuits of
12096-399: Was capable of reproducing clear tones, but later revisions could also reproduce muffled speech . Alexander Graham Bell patented his first electric loudspeaker (a moving iron type capable of reproducing intelligible speech) as part of his telephone in 1876, which was followed in 1877 by an improved version from Ernst Siemens . During this time, Thomas Edison was issued a British patent for
12208-481: Was denied patents. Being unsuccessful in selling their product to telephone companies, in 1915 they changed their target market to radios and public address systems , and named their product Magnavox . Jensen was, for years after the invention of the loudspeaker, a part owner of The Magnavox Company. The moving-coil principle commonly used today in speakers was patented in 1925 by Edward W. Kellogg and Chester W. Rice . The key difference between previous attempts and
12320-451: Was introduced to the market, subsequently replacing tube equipment as the mainstream technology. In the 1960s, the FTC with the help of the audio manufacturers came up with a definition to identify high-fidelity equipment so that the manufacturers could clearly state if they meet the requirements and reduce misleading advertisements. A popular type of system for reproducing music beginning in
12432-428: Was invented in 1925 by Edward W. Kellogg and Chester W. Rice . When the electrical current from an audio signal passes through its voice coil —a coil of wire capable of moving axially in a cylindrical gap containing a concentrated magnetic field produced by a permanent magnet —the coil is forced to move rapidly back and forth due to Faraday's law of induction ; this attaches to a diaphragm or speaker cone (as it
12544-504: Was launched in early 1925. Customers had a choice of oak, walnut or mahogany for the enclosure. One of French's brothers, Ralph, devised the name of the new product. He was also in charge of the cabinet designs and advertising, the two other brothers continued the plating business. A complete range with the models A1, A2, A3, A4 and A5 was introduced soon, and a subsidiary in Paris was formed, Constable-Celestion, to export first speakers. In 1927
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