The main types of loudspeakers

There are many kinds of loudspeakers, according to its energy exchange principle can be divided into electric (that is, moving coil type), electrostatic (that is, capacitive), electromagnetic (that is, reed type), piezoelectric (that is, crystal type) and other several, the latter two are used in rural wired broadcasting network; According to the frequency range can be divided into low frequency speakers, medium frequency speakers, high frequency speakers, these are often used in the speaker as a combination of speakers.

There are many kinds of loudspeakers, according to its energy exchange principle can be divided into electric (that is, moving coil type), electrostatic (that is, capacitive), electromagnetic (that is, reed type), piezoelectric (that is, crystal type) and other several, the latter two are used in rural wired broadcasting network; According to the frequency range can be divided into low frequency speakers, medium frequency speakers, high frequency speakers, these are often used in the speaker as a combination of speakers.

According to the energy exchange mechanism and structure of movable coil (electric), capacitive (electrostatic), piezoelectric (crystal or ceramic), electromagnetic (compression spring), electric ion and pneumatic loudspeakers, etc., electric loudspeakers have good electroacoustic performance, solid structure, low cost advantages, widely used;

According to the sound radiation material, paper basin type, cylinder type, diaphragm type; According to the shape of the paper basin, it is divided into round, oval, double paper basin and rubber folding ring; According to the working frequency, bass, alto, treble, and some are also divided into recorder special, TV special, ordinary and hi-fi speakers; The voice coil impedance can be divided into low impedance and high impedance. According to the effect, it is divided into direct and environmental sound.

Speakers are divided into built-in speakers and external speakers, and the external speaker is generally referred to as a speaker. Built-in speaker means that the MP4 player has a built-in speaker so that the user can listen to the sound produced by the MP4 player not only through the headphone jack but also through the built-in speaker. The MP4 player with built-in speakers can avoid the need for external speakers and the inconvenience caused by wearing headphones for a long time.

(1) Low frequency speaker

For a variety of different speakers, the requirements for the quality factor of low-frequency speakers - the Ω value are different. For closed and inverted boxes, the Ω value is generally between 0.3 and 0.6. In general, the larger the diameter, magnet and voice coil diameter of the low-frequency loudspeaker, the better the low-frequency replay performance and transient characteristics, and the higher the sensitivity. The structure of the woofer is mostly cone type, and a few are flat type. There are many kinds of diaphragm for subwoobass, such as aluminum alloy diaphragm, aluminum magnesium alloy diaphragm, ceramic diaphragm, carbon fiber diaphragm, bulletproof cloth diaphragm, glass fiber diaphragm, acrylic diaphragm, paper diaphragm and so on. The subwoofer using aluminum alloy diaphragm and glass fiber diaphragm generally has a small caliber and a large power, while the subwoofer using strengthened paper basin and glass fiber diaphragm has a more accurate timbral color and a good overall balance when replaying music.

Ω value: The quality factor of the speaker unit is a very important parameter that must be understood before the design and production of the speaker. On the impedance characteristic curve of the loudspeaker unit, it says that the sharp degree of the impedance peak at the resonant frequency of the impedance curve, which reflects the damping state of the loudspeaker vibration system to a certain extent, referred to as the Ω value, the higher the quality factor of the loudspeaker unit, the more difficult the resonant frequency is to control. The low-frequency characteristics of the loudspeaker are usually determined by the quality of the loudspeaker unit and the resonant frequency, where the size of the quality factor is related to the sound pressure output of the loudspeaker unit at the resonant frequency. When the Ω value is too low, the output sound pressure of the speaker drops rapidly when it has not reached F0, and the speaker is in an overdamped state, resulting in excessive low-frequency attenuation. When the Ω value is too high, the speaker is in an underdamped state, and the low frequency is excessively strengthened. The higher the Ω value, the steeper the peak value. Therefore, we say that the quality factor of the speaker can not be too high or too low, usually we take its critical damping value Ω equal to 0.5-0.7 as the best value range.

(2) Medium frequency loudspeaker

In general, as long as the frequency response curve is flat, the effective frequency response range is greater than the width of the sound band it bears in the system, and the impedance is consistent with the sensitivity and low frequency unit. Sometimes the power capacity of the mezzo is not enough, it is also possible to choose a mezzo with a higher sensitivity and a higher impedance than the subwoofer, thereby reducing the actual input power of the mezzo unit. Tenor units generally have two kinds of cone and ball top. It is just that its size and withstand power are larger than the tweeter unit and suitable for playing audio. The diaphragm of the alto unit is mainly soft materials such as paper basin and silk film, and occasionally there is a small amount of alloy spherical top diaphragm.

(3) high-frequency loudspeakers

The treble unit, as the name suggests, is a loudspeaker unit designed to play back high-frequency sounds. Its structural forms are mainly number solution, cone type, ball top type and aluminum belt type.