At present, there are more than 280 professional manufacturers engaged in speaker and speaker production abroad (according to AUDIO data), and there are thousands of products produced. Speakers and speaker systems serve as terminals for sound reproduction, and its quality will directly affect the sound quality of the entire sound system. The foreign companies engaged in loudspeaker production have invested a lot of energy and have continuously developed new speaker products to meet the higher requirements of different use environments and different audio equipment. In recent years, with the development of digital audio technology, the requirements for speakers have become more demanding. In order to meet the requirements of technological development and meet the needs of consumers, famous speaker companies around the world are committed to improving the performance of existing speakers, and researching and developing special new materials for loudspeakers, new processes and applying new design methods. Now the world is known about the status quo, characteristics and unique new technologies of the speaker and system technology of my company, as follows:

1. Foreign speaker and speaker technology status

1.1 Professional Loudspeakers

Mainly refers to speakers and speaker boxes used in movies, stage, halls, stadiums and other occasions. In recent years, with the development of new materials, new technologies, new structures, and new technologies, the application of stereo technology, digital technology, the popularity of CDs and VCDs, professional loudspeakers and their systems have also achieved great development, and new products are emerging. . The United States JBL, EV, BOSE company; UK KEF, TONNY company; Japan Panasonic, Pioneer, Mitsubishi, TOA, YAHAMA company, in recent years have launched a wide range of professional speakers and speaker systems. Their distinctive feature is that they have large power, all of which is above 200W; they have high efficiency, generally at 98-100dB; they have wide directivity.

In order to achieve the above characteristics, the world famous speaker manufacturers eight immortals, all show supernatural powers. The main methods taken are the following. First, the use of new magnetic materials, the use of new magnetic circuit design methods. Such as SFG magnetic circuit design used by JBL company, which contains a new structure of the magnetic flux balance, reduce the drive source inductance and heat conduction. The magnetic material used has a magnetic energy product of 3.6 MGsOe or more. This increases the capacity of the speaker to withstand power, and reproduces strong and powerful bass sounds. Second, the use of new materials, such as tweeter diaphragms for aerospace titanium materials, is superior to that of E.P. titanium materials and is suitable for the manufacture of high-quality treble diaphragms. With tweeters using titanium diaphragms, the high frequencies are greatly extended, and the power capacity is also greatly increased. Subwoofers use laminated high-density compound cones. The voice coil uses flat wire. Due to the high space factor of the flat wire and high utilization of the magnetic path gap, higher sensitivity can be obtained. The technology was invented by JBL and other major companies followed suit. Thirdly, with the new model drum, the exponential horn loudspeakers that have long been used in professional sound reinforcement have been replaced by new directional horns. The key technology of such directional horns is that the horns use different shapes of side walls. In the past, simple straight lines and exponential types have become complex and discontinuous function types to achieve constant directivity. Fourth, extensive use of computer CAD, CAM and CAT technology, the use of modern technology to tap the potential of traditional speakers, so that professional speaker products excellence. Representative products, such as JBL's MR professional speaker speaker series, SR professional speaker speaker series.

1.2AV speaker speaker

Mainly refers to speaker cabinets used in home hi-fi system, karaoke karaoke, ballroom, and home theater sound system. AV loudspeakers have made great progress in recent years, and new products are emerging. The world's major speaker companies have introduced various forms of AV speaker speakers. They not only have advanced technical performance, but also have technical characteristics such as practical modeling, increased sensitivity, expanded dynamic range, widened playback frequency band, and good transient response. There are two common crossover speaker cabinets: use a 8 inch rain or 6.5 inch midwoofer with a dome tweeter. Due to the common use of a loudspeaker in the low- and mid-range frequencies, the loudspeaker unit is required to have a wide range of piston vibration without segmentation vibration, so as to ensure ideal directivity and phase characteristics. According to the request of enthusiasts for the pursuit of bass, companies have developed dumbbell loudspeakers in succession, using a dome tweeter sandwiched between two 8-inch or 6.5-inch bass and bass units to enhance bass. Three-way crossover speaker cabinet: Adding a midrange unit on the basis of two-way frequency division, its advantage is to fully utilize the piston's vibration frequency band of each unit, reduce distortion, and improve the ability of power love. Another prominent feature of AV speakers is that they have good magnetic leakage protection performance. The magnetic circuit must have a magnetic shielding design to ensure that it does not affect the video image.

Today, the popular multi-dimensional stereo and home theater systems mean that the audiovisual effects of theaters are displayed in the average family. Surround sound is a part of it and it is an important part. The popular surround sound in the market is roughly divided into two types. One is the Dolby Pro-Logic surround sound evolved from the early “four-channel”; the other is the DSP surround sound originally developed by YAHAMA. DSP surround sound uses digital processing technology to simulate the sound effects of different spaces (such as a movie theater, a concert hall, etc.). This requires the front, center, and rear indicator speakers to be balanced and ideally directional.

Engineers in the electroacoustic industry have made unremitting efforts to improve the performance of AV loudspeakers. Through system design, experiments and simulations, they have continuously explored the mystery of the world of AV loudspeakers and ensured the objective parameters of loudspeakers on the basis of listening sensation. Occupy an important and necessary position. Representative products, such as JBL's home theater speaker speaker system, include a total of seven speakers in front of the main channel, center channel, surround channel, and subwoofer. The front main channel uses two 200mm woofer units, two 127mm midrange units, one titanium dome tweeter, and a horn tweeter. A horn tweeter is used in movie mode. The horn-type tweeter is used in the movie mode, and the titanium dome tweeter is used when listening to music. Replay sound quality design is very comprehensive, using multi-channel sound equalizer and 7-channel sound quality equalizer, using digital technology to create a magnificent theater sound in a smaller home space.

1.3 Subwoofer

In the past, designers used large cones as much as possible to achieve true bass output. Such as KLIPSCH company 27-inch subwoofer; EV company developed 30-inch conical subwoofer and so on. In recent years, the boom in the home theater audio market has driven the research and development of high-amplitude subwoofers. The representative products are: AURASOUND's 18-inch subwoofer with radial radial magnetic system. By controlling the thickness of the top plate and using a 0.5 inch voice coil in a 2 inch long magnetic gap, a large linear motion range is achieved. PINEER's subwoofer has a unique innovation. From the outside, people may think that it has no overhang. In fact, it attaches a structure like a hanging edge behind the diaphragm so that the diaphragm can be made in a cylindrical frame. Longer piston movement. The subwoofer's cone can be moved back and forth up to 2cm, 6-inch woofer, up to 100dB sound pressure level at 50Hz, which is difficult for traditional bass speakers. Representative products such as KEF's AV1 active active subwoofer.

2. The main features and unique new technologies of loudspeaker boxes of well-known foreign companies

2.1JBL Corporation

Speakers are characterized by: high power, 200-300W; high sensitivity, maximum sound pressure level over 110dB; good frequency response, flat frequency response and excellent transient characteristics.

Unique new technology:

(1) The magnetic pole core of the low-frequency speaker is rather thick, and the pole core is hollow. This specially designed magnetic pole core can reduce the weight of the speaker and facilitate heat dissipation, aiming to improve the power carrying capacity.

(2) The flat line voice coil, as an advanced technology, was invented by JBL. Originally used on subwoofers, it was also commonly used in tweeters, both aluminum and copper. The flat wire has a high space factor and high utilization of magnetic voids in order to increase sensitivity. According to the test, in the same magnetic circuit, the flat wire voice coil can improve the sensitivity by about 1 dB compared with the round wire voice coil.

(3) Titanium diaphragm dome-type unit, but also the JBL company first started successfully. The Young's modulus of titanium is superior to that of aluminum. With a tweeter using a titanium film, the upper limit of the high frequency can be broadened, and the power capacity is greatly increased.

(4) SFG Symmetric Magnetic Field Magnetic Titanium diaphragm is a patented technology of JBL. The patented technology ensures that the symmetrical distribution of the FB ＆#118alue on the magnetic gap is equal to the upper and lower positions of the voice coil, and it includes the configuration of the magnetic flux balance, the reduction of the inductance of the driving source and the heat conduction. Effectively suppress low frequency distortion, improve power endurance and damping characteristics.

2.2BOSE Corporation

The company's speaker box features: Active use of the sound of the listening environment to improve and modify the speaker's radiation characteristics, developed the world-famous sound field type speaker box.

Bose's new technology:

(1) Direct/reflecting speaker technology. The bose sound box uses direct/reflective technology to restore mixed sounds that are reflected from the walls, ceilings, and floors to the listener, using direct/reflective theory to express the sound levels and performance. Representative products are the 901, 701 and 501 series speakers.

(2) Sound air flow Bass technology. This technology uses the airflow generated by the "A-cousticMass" structure and is coupled with three independent acoustic chambers to reduce the resonance of the woofer diaphragm, reduce distortion, and provide a large dynamic range.

(3) Audio Waveguide Technology. This technology is the research result of Bose Company after 14 years of research and applied for a patent. Its feature is that it installs a long, splayed deflecting waveguide in a minimal chassis structure, thereby increasing the low-frequency feel and creating a huge sense of stage space that breaks through the small box volume limit.

(4) HOROFINE thin film technology. This thin-film technology is made from bamboo pulp and wood pulp. It has perfect, balanced plasticity and rigidity, and it can meet three main criteria for converting electric signals into high-quality sound waves: low density and high Young's modulus. With a large decay index, it can reproduce bright, clear and natural sounds in the mid-high range.

2.3AR Company

The company is known for creating air-cushioned loudspeaker enclosures that use acoustic suspension technology to support deep bass by supporting the bass unit in an airtight enclosure. This speaker box has been around since the 50 years and has been used for a long time.

2.4 France FOCAL Group Corporation

The company is known for creating advanced speaker units and also produces a wide range of speaker boxes that are sold worldwide. Some group companies have advanced speaker manufacturing technology. There are four important internationally recognized inventions.

(1) Invented a new design called "MVF" (Eliminate Mechanical Oscillation) system. The use of this system overcomes the shortcomings of the mechanical sounding of conventional cone-type loudspeakers and reduces the intensity of splitting the cones to ensure high-fidelity playback.

(2) In the diaphragm design, Polkevlar cones with registered patents are of light weight and high rigidity, which completely solves the problem of sound and dyeing and the frequency response is accurate.

(3) The Polyglass (polyethylene glass) treatment cone was invented to make the cone highly rigid and have excellent internal damping characteristics, so that the sound of the unit is smooth and natural, and the replay of music is detailed and accurate.

(4) The newly developed Diamond Diaphragm in the 1990s can replay beautiful sounds.

The speaker of this company is characterized by high sensitivity, and most products are more than 90dB. The midrange and tweeter units are coaxially mounted on the centerline of the panel, producing accurate audio and video.

2.5 Danish DALI Company

The Division attaches great importance to the audiometry program of the speaker, and it is not only based on the objective test results. The company has an audiovisual judging panel composed of experienced people with professional music literacy, making a subjective assessment of the sound quality of each new DALI product to ensure the unique style of DALI products. The most prominent features of the DALI speaker are: the front panel is as narrow as possible, and the sound diffusion angle is controlled; the cabinet is very hard and has a surface absorption layer device, which can effectively eliminate the resonance, stabilize the sound field, and have a very accurate stereo sense. The units used by the speakers are paired by computer tests.

2.6 British speaker characteristics

TANNOY Coaxial Loudspeaker is well-known worldwide and successfully solved the problem of phase distortion; KEF invented the "UNI-Q" coaxial technology to achieve the ideal of both treble and bass co-axial sounding, making the stereo image accurate; QUAD specializing in the company Electrostatic speakers have spared no effort to improve and develop it; Celestion and Rogers' small speakers have a 2 dB bump at 2000 Hz. Some people believe that this slight difference will definitely affect the timbre, but the two companies' The product is a representative product of a British small box, which may be the secret of the British sound.

2.7 New Flat Panel Speakers

British verity company and NCT company, in 1996 announced the successful development of a new ultra-thin flat panel speaker, which is indeed a major breakthrough in loudspeaker production technology. This type of flat panel speaker has a thinnest thickness of 3mm and a thickness of no more than 25mm. The effective radiation area size can be determined from design, from 25cm2 to 100m2. Verity's NXT loudspeaker uses an electromagnetic actuator and NCT The company uses piezoelectric ceramic actuators. The vibration plate uses carbon fiber and paper materials, and the speaker is very lightweight. The frequency response range of the speakers is very wide, which means that each angle is large and the sound quality is good. This flat panel speaker does not require a cabinet and can be like a painting hung on a wall or installed in a ceiling. Experts predict that such ultra-thin flat panel speakers will have a good application prospect and will become the new generation of speakers in the 21st century.