Gold Ribbon has made the ribbon driver with the largest bandwidth (200Hz-30KHz). Instead of aluminum, they made the diaphragm out of gold with a thickness of only 1 micron (one millionth of a meter). But the most successful company is Apogee. Jason Bloom, who is both an art agent and an audio player, and his father-in-law Leo Spigel, a retired aviation engineer, formed Apogee. They use a classic ribbon driver for the tenor and another quasi-ribbon driver below 100Hz. In recent years, they also added cone and basin bass to mix and match the design, and the evaluation is quite high. In addition, there is a distant relative of the ribbon horn family-BES (Bertagni electroacoustic system) pulsating diaphragm horn. BES, like a typical electrostatic speaker or Magneplanar planar speaker, has an open shelf and a planar diaphragm, and the sound radiates forward and backward. However, BES is not a very thin metal plate, but foam plastics with different thicknesses, which looks a bit like a three-dimensional map. BES design makes the surface of the diaphragm have many resonance modes, and different parts of the diaphragm vibrate at different frequencies. The vibration mode is not a mechanical piston, but a tuning fork that vibrates evenly with a wide audio frequency. The design of BES caused a lot of controversy, and of course it ended in nothing. During the evolution of the strip horn, the plane dynamic horn, the so-called fake strip horn, has also evolved, and its appearance is attributed to Jim Winey, an engineer of American 3M Company. Jim Winey was originally an amateur audio lover. He likes electrostatic speakers very much, but he thinks KLH-9 is too expensive. There should be a way to reduce the cost. One day, he was inspired. He found that soft ceramic magnets used for refrigerator doors are light in weight, low in cost, easy to cut and manufacture, and very suitable for magnetic structures. This kind of magnet can uniformly drive the whole flat and wide diaphragm surface, and can be used in the plastic diaphragm horn with bipolar radiation. There are many tiny wires on the horn diaphragm designed by Jim Winey. The metal wire receives the signal from the amplifier and cooperates with the magnetic field of the permanent magnet to generate suction and thrust. 197 1 year, Winey officially launched a new speaker, which was first named "Magnestatic" and later renamed "Magneplanar". Magneplanar received a great response after its listing, including Strathearn, Wharfedale, JVC, Cerwin-Vega, Thorens and other companies have developed different types of planar dynamic speakers, the most famous of which is Infinity. Infinity's quantum reference standard is equipped with a double amplifier and an electronic sound separator. It is composed of many small diaphragms, not a complete diaphragm. QRS is two meters high and one meter wide. A * * has 20 high-pitched units, of which 13 is forward and the rest is backward, which are vertically arranged in a straight line. Alto has three monomers, which are also arranged vertically. Coupled with a bass of 15 inch, QRS can produce extremely shocking volume, and the frequency is beyond the audible range. Later EMIT and EMIM alto were also flat diaphragms, which were different from the later tenors used in Genesis. The tenor in Genesis can be regarded as a mixed design of ribbon monomer and flat monomer, while the megaphone in Genesis adopts ribbon monomer, which is different from Wuji. However, we can see that the giant speaker architecture built by Infinity from IRS is still the highest model of Hi-End speakers for so many years. Flat speakers also have their limitations. Its magnetic structure makes only the marginal flux of the magnetic field interact with the "voice coil" distributed on the diaphragm, so its efficiency is not high. So far, this phenomenon can exist. On the other hand, the diaphragm used by planar speakers is heavier than electrostatic speakers or ribbon speakers, which will limit their bandwidth. In the past, only Audire Company used a full-range plane driver, even Magneplanar's own speaker, and later it was combined with a single medium-high tone and a flat diaphragm bass. Burwen and Yamaha of Japan once made headphones with flat diaphragm. Pioneer gave up magnetic flat and used polymer as headphones, but these products did not seem to be affirmed. One of the most successful non-traditional speakers is Haier's design. Shortly after Winey completed the first plane dynamic horn, the German physicist Oskar Heil developed an elegant strip horn variant, which he called the air motion transformer.
Haier's invention is very similar to a planar dynamic horn, which uses a thin plastic diaphragm covered with a conductive aluminum "voice coil". However, the diaphragm of Haier horn is not tight, but pleated and loosely hung on the shelf, so the steel wire voice coil is located in the gap between a pile of vertical magnets. When the magnetic force alternately squeezes the curved and wrinkled diaphragms and then pushes them away, the air squeezes together with the audio. This design has high efficiency, and the strong magnetic force on the diaphragm can reduce the effective mass reactance or audio impedance, which is also the origin of the name "pneumatic transformer". In fact, this kind of loudspeaker is a sound converter. Just like a horn, its high frequency can extend upward because of its low effective mass. The bandwidth of an ordinary Haier driver is 300 Hz-25 kHz, and there is no need for equalization at all. Although Dr. Haier is full of confidence in his own design and thinks that his own speakers are reasonable and others' speakers are strange, Haier speakers gradually fade out of the market due to poor quality control and poor bass monomer coordination. When faced with many unknowns, Rice and Kellogg of Danbert Lab are probably the most awesome monsters known as singing arcs or circular discharge angles. As early as 1920s, radio technicians found that the high-voltage electrical signal used to modulate the transmitter sometimes formed blue spherical luminous gas, and the broadcast sound would be emitted from the luminous sphere, with a small but clear sound. Some people describe it as like a fire. Rice and Kellogg did not study this phenomenon seriously, because this pronunciation device has insufficient bandwidth and emits a lot of ozone. 1940s, French nuclear physicist Siegfried Klein discovered this phenomenon again and tried to develop a new horn. 1950, he named the new product "ion horn". This design has no mechanical resonance, no mass and infinite obedience, which seems to be a major breakthrough of the horn. Decca in Britain, Audax in France, Telefunken in Germany, Fane in Britain and Realon in Japan all devoted themselves to the research of ion horn, but Dukane (electronic sound) in the United States was the first to be commercialized. They launched a new product called Ionovac at 1962, which was later produced by AmericanAudioC om. It lasted a long time. As for Siegfried Klein, who was not involved in the production, he continued to study the magical ion horn, which, like candlelight, can be blown hard without destroying the music. Another advantage of ion horn is its high efficiency. The sound pressure of 105dB can be achieved only with an amplifier of 10 watt, and the frequency response can also be reduced to about 1000Hz. Siegfried Klein's design was produced by Magent in Germany, but it was banned from being sold in the United States because of the excessive ozone and another brand of Hill Plasmatronic threatening Magent's monopoly position. The principle of plasma horn designed by laser physicist aaron hill is the same as that of ion horn designed by Siegfried Klein. The quartz tube filled with special gas produces discharge phenomenon, which ionizes the air and makes sound. In the simplest way, their vocal process seems to be a phenomenon of thunder after lightning. This horn has excellent high-frequency characteristics, but the quartz tube has a limited life (helium needs to be replenished every few months), which is costly and inconvenient to use. Hill's ion horn has a frequency of 700 Hz-20 Hz, and there is still a sound pressure of 90dB at 10 feet. The bass is handed over to the traditional cone-basin horn. This pair of loudspeakers has perfect phase and amplitude linearity, and the distortion is less than 65,438 0%. Unfortunately, the price is as high as 10000 USD (including class A amplifier to push the tweeter and electronic frequency divider). Of course, few people buy it. However, the ion horn of Hill and Magent still exists in the market for a long time. The real conical horn 65438+Walsh introduced by Ohm in 0985 is as creative as BES, and it is also the first pair of real conical horns. Not only the conical monomer is used, but also the horn itself is conical. Walsh only uses a single unit to deal with the wide frequency of 20 Hz-20 kHz. The conical driver is placed on the top of the speaker, with the voice coil and magnet on it, and the diaphragm faces the inside of the speaker. Walsh works in the controlled decomposition mode, and when the frequency rises, the range of the paper basin responding to the voice coil decreases; When the frequency is low, the moving range of the paper basin increases.
If this goal cannot be achieved, the paper basin is composed of several concentric rings made of different materials, and the concentric rings are equivalent to bass filters. The larger the ring, the lower the processing frequency, and the lowest frequency makes the whole paper basin move; The high frequency is only maintained by a very light diaphragm, and the frequency response is kept flat by damping. This design has good linearity in both phase and amplitude, and the most important thing is that it can emit 180 degree sound. Another example of conical horn is the 10 1 horn of mbl, Germany. 1975 or so, Meletzky, the boss of a computer instrument control company, found that the spherical monomer can best meet his ideal, and the diaphragm of the spherical monomer is larger than that of the traditional speaker monomer, which can better simulate the performance of natural instruments in space. So he teamed up with two professors from the University of Berlin to make a round monomer similar to a pleated skirt out of aluminum. This product named 100 has not been officially launched. 1987, mbl made a 360-degree sounding tenor monomer with carbon fiber, and then combined with a gourd-shaped bass made of several aluminum sheets, launched an amazing 10 1 speaker. There is also a positive horn, in which a light aluminum strip is stuck on the whole plastic film and then placed in a strong magnetic field, and the aluminum strip is electrified to produce vibration and sound. 19 19, American physicist Arthur g Webster invented the exponential horn. Because of its high efficiency of 50% (the efficiency of the general moving horn is only 1- 10%, and the efficiency of the Horn horn of Klipsch is about 30%), it is quickly widely used in theaters, stadiums and other places that need large volume. Horn horn is characterized by its high efficiency, and it can make a great sound with a little power. Its disadvantage is that it is not conducive to low-frequency playback. If you want to play low frequency, you need a long speaker. For example, to play back 50Hz frequency, the diameter of the speaker opening should be two meters and the length should be more than five meters. 1940, American engineer Paul W. Klipsch designed a small folding subwoofer suitable for home use. The driver is installed in the corner of the room, and the wall of the room is regarded as an oversized speaker. When Klipschorn celebrated his 50th birthday, the loudspeaker was still in production. Altec Blue Star, founded in 1927, is another legend of loudspeaker. 1956 released A7 The Voice of the Theater, which is still popular today. Vitavox, founded in 1932, launched a loudspeaker comparable to Klipschorn in 19 1 horn horn. The frequency response has reached 20 Hz-20 Hz, and it is still in production progress. The characteristics of the horn will vary with the length, shape and materials used. From the early iron-aluminum-zinc horn, it gradually evolved into plastic, cement, wooden horn, synthetic material horn and other materials. Proper design can partially solve the problem of poor sound quality of horn speakers; Improper design may even lead to a roaring effect. Trumpets can be divided into hyperbolic, parabolic, exponential and conical shapes, among which exponential angle is the most commonly used. Some speakers are too directional, so an acoustic lens must be hung at the front end to increase the angle of sound diffusion. Some simplified folding horns have been put forward one after another. Some designs use short speakers and room walls to enhance the low frequency emitted from the back of the speakers, and at the same time directly emit medium and high tones from the front of the cone basin. This kind of folding horn with a load on its back usually works well. At present, speaker speakers are mostly used in conjunction with cone bass. Because the efficiency of the horn is usually above 100dB, it is not so easy to use. The more successful manufacturers are JBL from Northern Europe, Dianyin, Einstein, Jadis from France (the unique Eurythmie 1 1 is enough to go down in history), West Lake from the United States and Zingali from Italy. In addition to the improvement of the air cushion horn itself, engineers have been thinking about it since the 1950s, hoping to show better results with the same monomer.
There are two of the most famous designs, one is an air cushion horn and the other is a transmission line horn. With the appearance of 1958 stereo record, stereo has entered the three-dimensional world. Unlike singers, speakers need to be redesigned. Consumers only need to buy one more speaker of the same type. But because of this, the huge horn is no longer popular, and everyone needs new products with small and low frequency, so the air cushion horn comes into being. The hero behind the popularity of air cushion horn should be crystal amplifier, which provides high power without heating to cope with the inefficiency caused by air cushion design. At the same time, the air cushion horn is also the culprit behind the high power expander. Many people had this idea in the 1970s. It's not good if it's not a high-output amplifier, and it's not advanced enough if it's not an air cushion horn.
The air cushion type is also a closed design. When the monomer is moving, if the backward wave propagates to the front, it will cause the low-frequency signal to cancel, so the concept of infinite baffle is produced. A closed box can also be used as an infinite barrier to minimize the chance of interaction between front and back waves. Bass reflex is a derivative design of infinite baffle. Because the size and vibration frequency of the cone will limit the low-frequency performance of the speaker, installing a speaker with an opening can expand the low-frequency response. The size of the opening is determined by the volume of the speaker and the vibration frequency of the monomer. When the speaker reflects the phase shift of the sound, the low frequency emitted by the opening and the cone basin is the same, resulting in the enhancement effect.
Edgar Villchur, founder of AR in 1954, introduced the air cushion horn, which solved the problem of rapid attenuation of low frequency caused by rigid air in general closed speakers. The moving coil is usually composed of a cone and a voice coil, and the edge of the cone is supported by elastic materials, so there can be no free air vibration frequency. If the airtight loudspeaker is filled with sound-absorbing material, the loudspeaker system will produce higher vibration frequency than a single driver. Edgar Villchur put the monomer with free air vibration frequency of about 10Hz into a closed loudspeaker with 1.7 cubic feet, and the vibration frequency of the loudspeaker was increased to 43Hz. On the one hand, this design greatly reduces the distortion of the system, on the other hand, it can emit deep low frequency, and the disadvantage is that the efficiency is greatly reduced. Transmission line horn was originally called labyrinth design, and the horn monomer was installed at one end of the speaker. Through the complex and long tuning channel, the echo of the monomer diffuses from the opening at the other end. The first maze design was designed by Ban Jieming olney for Stromberg Carson Company in 1936. He put a * * * monomer with a vibration frequency of 50Hz into a labyrinth speaker, and as a result, its * * * vibration frequency was reduced to 40Hz. At the half wave of 40Hz, 75-80 Hz, a good bass was produced. But at the same time, he found that the response curve produced many peaks, which came from the sound of the speaker channel itself, so he laid sound-absorbing materials and baffles in the channel and cut off the frequency above 150Hz at the opening. Labyrinth design can get a good bass extension, but it is troublesome to make and not as competitive as the simple closed design of economical bass reflex, so Carson popularized labyrinth design again in the 1950 s, but it still failed. When the labyrinth horn reappeared in the mid-1960s, it had a new name-transmission line horn.
The transmission line type can be said to be a labyrinth filled with dampers in the channel, and its theory was put forward by Professor A.R. Bailey of Bradford Institute of Technology. He thinks that the bass reflex speaker is easy to ring because of the severe attenuation of the low frequency, just like suddenly cutting off the low frequency by electronic means. If an infinite channel is designed behind the speaker to absorb the reflection of the back wave, the interference standing wave can be eliminated, so he replaces the infinite channel with sound-absorbing and damping materials such as long fiber cotton, and extremely low-frequency sound waves can escape from the channel, which enhances the low-frequency effect of the speaker. Professor Bailey's design has been adopted by many manufacturers, including IMF, Infinity, ESS, Radford and so on. Some of them use this channel to enhance the bass, while others use it to damp it. The cross-sectional area of the labyrinth outlet is usually equal to or greater than the area of a single baffle; The channel of transmission line type decreases gradually, and the cross-sectional area of outlet is smaller than that of diaphragm.
Robert Fris of Britain once recommended a variant design of transmission line, which is called "decoupled antiresonant line". This design claims that there is no ringing phenomenon, and good bass can be obtained by using small-sized monomer, and it also has better instantaneous effect than large-sized monomer. At present, there are no speakers designed by Darling, but some bass reflex speakers have been inspired by this and improved. People who are used to closed or bass reflex design have always had opinions on transmission line design. The design of transmission line is bulky, complicated and unpredictable, which also hinders its development. At present, only British TDL (former International Monetary Fund) and PMC are well-known manufacturers of transmission lines. PMC successfully designed a recording studio listening speaker with transmission line, which once again aroused everyone's interest in transmission line. The loudspeaker unit has gradually developed from a single full-range design to a multi-channel design. Engineers found that there are many problems in the connection between different frequency units, including frequency division point, frequency division slope, sensitivity, phase, etc., which may cause errors, so they put forward two new thinking directions, one is full-frequency speaker and the other is coaxial speaker. Goodmans in Britain once asked Jordan to design AXIOM80 monomer, which is designed for recording and listening, and is also an evergreen tree with a full range of monomers. Jordan and another Englishman, Watts, formed the Jordan Watts Company at 1964. At that time, the model unit monomer was continuously produced for more than 20 years. This monomer uses a 10 cm metal diaphragm, a voice coil made of beryllium bronze, and a square frame, which is very distinctive. Jordan Watts' hip flask vase-shaped full-range speaker introduced in 1975 is still in production today, and it is one of the few speakers like works of art ... Wharfedale, founded in 1932, also introduced a good full range of monomers before and after World War II. 1958 after the change of boss, it began to develop into cutting-edge technologies such as computers and gave up the development of a full range of monomers. Lowther, another British company, has always insisted that it has been immersed in the whole series of monomer fields for more than 60 years. Their products can still be bought in Taiwan Province province because of their single features such as white independent edge and central equalizer.
There are many full-range monomer manufacturers in Japan. Coral, once known as the three old stores of speakers with Pioneer and Anqiao, has launched a full range of monomers with a size of 20 cm. Diatone became the first company to produce full-range speakers after the war in 1946, and they achieved great success by using OP magnets. 1947 cooperated with NHK to develop P-62F monomer for listening and broadcasting. Later changed to P-6 10. The whole series sold well for nearly 40 years and became a legend in Japanese audio history. On the eve of celebrating the 50th anniversary, Diatone launched a limited edition commemorative product, which caused a small sensation. Fostex, which was separated from Foster Automobile on 1973 due to the oil crisis, has produced many creative products, such as double cone basin full series monomers, biological diaphragm monomers and so on. They also made the world's largest bass unit EW800(80 cm). Guy. R. Foundtain founded tianlang company in 1926, and the LSU/HF/ 15L monomer designed by 1947 is a coaxial design with two channels, with a size of 38 cm, which opens a new era of coaxial speakers. 1953, Tianlang began to manufacture coaxial single listening speakers for recording studios such as Monitor 15 Silver, which were adopted by many major record companies. Many Dika's burning discs were recorded with Tianlang speakers of this era. Tianlang's coaxial concept comes from the design of full-range point sound source in 1930s. It has the advantages of simple structure, good linear symmetry and directivity, low distortion and accurate audio and video. In order to get enough bass, Tianlang continued to increase the size, and finally applied 38 cm coaxial monomer to top speakers such as the Royal Westminster, which can produce quite low frequencies. In recent years, Tianlang not only designed a coaxial monomer with dual voice coils, but also installed a tulip waveguide in the tweeter monomer to improve the smoothness of frequency response. On the occasion of the 70th anniversary of Tianlang, they launched a new flagship kingdom speaker, and the midrange part still adopts coaxial design. In addition, with the addition of ultra-high and ultra-low monomers, this speaker also illustrates the limitations of coaxial design.
Tianlang's biggest competitor is British compatriot KEF(Kent Engineering and Foundary), and their actions are more active than Tianlang's. 1984 introduced the coupled Caviy technology, and the unique concept and rich low frequency of 104/2 speaker caused many discussions. This year, they joined the coaxial speaker market. 1989, KEF further improved and introduced the coaxial technology named uni-q. 105/3 loudspeaker uses cavity coupling technology and Uni-Q monomer at the same time, which shows a higher level. KEF's Uni-Q monomer is equipped with two magnets, a big magnet and a small magnet, and the tweeter uses the bass diaphragm as the speaker to achieve the purpose of coaxial synchronization. Tianlang's coaxial monomers are not on the same plane, so they are not really coaxial at the same time.
Various coaxial designs emerge one after another. Gauss, who specializes in manufacturing PA and studio speakers, added a bowl-shaped cover to the treble and placed it in the middle of the bass. The evaluation was good. Siemens in Germany also designed a coaxial monomer, which placed a 9 cm high-pitched monomer in front of a 25 cm low-pitched monomer, and then used an acoustic lens to increase the diffusion angle. Entering the drama market in the 1970s caused a great discussion. Piezoelectric monomer is only used in a few high notes at present. Piezoelectric refers to materials that expand, contract or bend when a voltage is applied, such as compounds, such as Rochelle salt, barium titanate, titanate, zirconate, etc. , has been used in components such as singers and headphones. As for the horn, it will not be realized until the polymer made of polyvinyl fluoride resin, which can be stretched axially and vacuum evaporated on both sides, appears. This monomer has good linearity, small distortion and good real-time performance, and can be designed into various shapes because of its light weight. Its disadvantage is capacitive impedance, and sometimes it needs a specially designed switching amplifier.
In addition, there are air valve speakers (allowing air from compressed air tanks to flow through the speakers to make sound), induction type, thermal friction type, and officially commercialized film type. Philips of the Netherlands has introduced an MFB horn, which is equipped with an amplifier and active feedback components in the horn box, extending the feedback loop of the amplifier to the horn voice coil. Philips' products were not successful, but it inspired Infinity, Genisis and other manufacturers to make servo amplifiers in the bass part to reduce bass distortion.