Analysis on the development trend of Chinese speaker technology

1.1 Current situation analysis of loudspeaker technology development

1.1.1 AVSpeaker analysis

Is mainly used for home hi fi audio system combination, karaoke OK karaoke, dance halls and home theater sound system of speaker.AV speakers over the past few years has made great development, new products continue to emerge. Speaker companies around the world have launched a various forms of AV speaker system. They not only have advanced technical performance, but also from the practical shape, the appearance of the decoration to the color contrast has the characteristic. The design of loudspeaker system is widely used in computer CAD technology to achieve the technical characteristics of reducing distortion, improving sensitivity, expanding the dynamic range, broadening the playback frequency band and good transient response. A 8 inch or 6.5 inch bass unit with a inch or inch high frequency divider is used to ensure that the loudspeaker unit has a wide range of piston vibration and does not appear to split the vibration. The company according to the pursuit of enthusiasts bass and have developed a dumbbell type speaker system, with two 8 inch or 6.5 inches bass unit between the clip a dome tweeter. Aims to strengthen the bass. Three 2-way loudspeaker system: in two frequency based on a mediant unit, the utility model has the advantages of is make full use of each unit of piston oscillation frequency, reduce the distortion, improve the power to bear ability.AV speaker another notable feature is with good leak proof magnetic properties and magnetic to magnetic shield is designed to ensure that does not affect the video image. Today, popular multidimensional stereo and home theater system is to show the cinema audio and visual effects in the general family, surround sound is part of, and is a very important part. The market is now popular around the sound is generally divided into two kinds, one is the early "four channel" evolution of the Dolby directed logic surround sound; the other is the first YAMAHA company developed DSP surround sound. DSP surround sound is a digital processing technique to simulate different spaces (e.g., a cinema, a concert hall...... The sound effect. This requires the front, middle and rear speakers sound system to balance, pointing to the ideal. Acoustic boundary engineers to improve the performance index of the AV speakers were unremitting efforts, by means of system design, experiment and simulation, and continuously explore the mysteries of the AV speakers in the world, in which on the foundation of listening, to ensure that the speaker objective parameter occupies an important and necessary role. Representative products, such as JBL company of home theater speaker system, including pre main channel, mid channel, surround the sound track and ultra bass of a total of seven speakers. Front main channel with two 200mm bass unit, two 127mm mediant unit, a titanium film ball top tweeters and horn type high tone loudspeaker. Movie mode using the horn tweeter, enjoy music using titanium diaphragm ball dome tweeter. Playback of the sound design very comprehensive, using the multichannel sound equalizer and a 7 channel sound equalizer, the use of digital technology in small family space create the majestic theater sound.

1.1.2 Heavy bass loudspeaker analysis

In the past, in order to achieve the true bass output, the designer uses the large vibrating basin as much as possible. Such as KLIPSCH's 27 inch ultra bass speakers; EV company developed 30 Inch Tapered super bass speakers, etc.. In recent years, the booming home theater sound market research and development of the large amplitude of the ultra bass speakers. The representative products are: AURASOUND radial magnetic system of 18 inch ultra bass speakers. By controlling the thickness of the top plate and using a 0.5 inch English ring in the 2 inch long magnetic gap, a large linear range of motion is obtained. PINEER SUBWOOFER SPEAKER unique initiative, from the appearance, people may think it has no dangling edges. In fact, it will be similar suspended edges paste structure after the diaphragm, let diaphragm can in the cylindrical framework for a longer period of the piston motion. The introduction of manufacturers said that super bass speaker vibrating basin before and after exercise up to 2 cm, 6 inch diameter woofer, at 50 Hz up to 100dB SPL. This is difficult to achieve the traditional woofer. Representative products, such as KEF's products AVI active ultra bass sound box.

1.1.3 Car speaker analysis

With home audio, car audio with electrical performance, has reached the level of fidelity. In view of the unique characteristics of automotive interior environment, the general type loudspeaker can not meet the needs of the high fidelity reproduction. The outstanding feature of these speakers is that high power, high temperature, humidity, can fire, anti aging, high reliability. Many famous brand speaker manufacturers, such as ALTEC, EV, JBL, Panasonic, FOCAL, FORSTER and other companies, have long been to produce professional and AV speakers said in the world. In recent years, the use of its technological advantages to develop the use of speakers and speaker systems, products with its high quality reputation worldwide. Representative products, such as BOSTONACOUSTICS75N car speakers, the car speakers are composed of 5.25 inch bass unit and 0..75 inch high unit. The high bass unit uses a composite polymer membrane colloid new, has excellent resistance to aging at high temperature. MARA-NTZLS-10VS car speaker system and the system of speaker special solid plastic, adding calcium carbide polymer casting and frequency equalization circuit, the loudspeaker unit with high temperature resistant special adhesive meter.

1.1.4 Multimedia speaker analysis

Mankind is marching into the information society, both developed and developing countries, to speed up the development of electronics and information technology industries. With the expansion of the market for ultra compact high fidelity audio equipment and multimedia computer applications, the demand for small portable speakers is becoming more and more popular, especially for the development of multimedia speakers. The speaker is characterized by a magnetic shielding function, and an internal power amplifier. Representative products, such as ALTEC ACS100 and ACS150 multimedia speakers, these two models all have magnetic shielding function, digital signal processing circuit (DSP) and power amplifier.

1.1.5 Analysis of thin micro speaker for communication

With the booming development of the world telecom and computer industry, the market demand for the polyester diaphragm loudspeaker is steadily increasing. In order to meet the growing market demand, manufacturers in Asia invested more funds, for the development of thinner, more durable polyester diaphragm speakers and expand production capacity, polyester diaphragm loudspeaker is mainly for telecom equipment, pagers and high fidelity headphone, but now also for notebook computer production of polyester diaphragm loudspeaker. The global Notebook PC requires a 2400 - year - A - year - rated speaker of the polyester diaphragm. The high - power, high - power, high - power, polyester, 0.5-1W, has become increasingly popular. The popularity of cellular phones, promote the broadband voice (300Hz-4000Hz), highly sensitive, low distortion, the development of thin polyester diaphragm loudspeaker. In order to meet the needs of the car mobile phone, there are already manufacturers to produce high temperature resistant polyester diaphragm loudspeaker.

1.1.6 Flat panel speaker analysis

A.NXT，The speaker unit uses a technique called distributed wave mode (DM) technology, which makes the directivity of the medium and high frequency is reduced, the acoustic radiation tends to plane wave, and the high frequency characteristic is not affected by the film quality. It does not need to use the box, so it saves space (but may have some requirements). The particularity of the vibration film makes the amplitude is small, so it can reduce the harmonic distortion caused by nonlinear vibration, and overcome the resonance, and reduce the "sound"".

B.NCT,The flat panel speaker, known as the NCT (noise elimination technology), was developed by a US company. NCT uses a special ceramic substrate to drive the "flat" sound, which is spread along the surface of the plate, and the sound is good. Allegedly using NCT flat panel speakers, in any position in the room, the sound source of the front or rear, are able to get the same sound effect, the NCT prototype thickness of only 3mm, its use and installation flexibility, decorative, to the speaker designers left a huge re create space.

C. The common characteristic of NXT and NCT is that the low frequency limit is in inverse proportion to its vibrating membrane area. At present, it is necessary to obtain the 20Hz low frequency and the vibration film area is equivalent to a large wall.