Louder speaker, commonly known as loudspeaker, is an electroacoustic device that can convert electrical signals into sound, and is an important equipment in the sound system. As one of the electroacoustic energy conversion devices, the quality and characteristics of loudspeakers play a decisive role in the sound quality of the whole sound system.
Due to different materials, technologies and working principles, loudspeakers can be divided into many types, including electric speakers, magnetic loudspeakers, ion loudspeakers and electrostatic louder speakers.
Today, I'd like to introduce these 10 kinds of louder speakers which are widely used in home and professional fields
1. Electric louder speaker
This kind of louder speakers are the most widely used, which can be divided into paper basin type, horn type and ball top type.
2. Paper cone louder speaker
The paper cone loudspeaker is also called moving coil loudspeaker. It consists of three parts
① The vibration system includes a cone-shaped paper basin, a voice coil and a centering support piece;
② The magnetic circuit system includes permanent magnet, magnetic guide plate and field core pillar;
③ Auxiliary system, including basin rack, wiring board, blank holder and dust cover, etc.
When the voice coil in the magnetic field has an audio current passing through, it will produce a magnetic field which changes with the audio current. This magnetic field interacts with the magnetic field of the permanent magnet to make the voice coil vibrate along the axial direction and produce sound. The loudspeaker has the advantages of simple structure, full bass, soft sound quality, wide frequency band, but low efficiency.
3. Horn louder speaker
The horn type loudspeaker is composed of vibration system (treble) and horn. The vibration system is similar to the paper pot loudspeaker, except that the diaphragm is not a paper basin, but a dome shaped diaphragm. The vibration of the diaphragm radiates sound waves into the air through the horn (after two reflections).
It has the advantages of strong directivity, high power and high efficiency, so it is widely used in venues, fields, vast fields and other occasions. Professional high-frequency horn loudspeaker has the characteristics of good sound quality and good frequency response, which is mainly used in theatres and other demanding occasions.
The disadvantages of horn loudspeaker are poor low frequency response, narrow frequency band and easy to produce nonlinear distortion. The main difference between the horn loudspeaker and the paper pot loudspeaker is indirect radiation, that is, after the vibration of the vibrating membrane, the sound will be diffused outward through the trumpet, so that the sound will be greatly enhanced, and the sound will be concentrated in one direction, so that the distance of sound transmission will be further.
4. Dome loudspeaker
The spherical dome loudspeaker is one of the most widely used electric speakers in the loudspeaker box. Its biggest advantage is the excellent mid high frequency response and wide directivity. In addition, it has the advantages of good transient characteristics, small distortion and good sound quality. The dome loudspeaker is suitable for all the home theater series speakers on the market.
5. Magnetic loudspeaker (reed loudspeaker) magnetic loudspeaker is also called "Reed loudspeaker". In the structure of magnetic loudspeaker, there is a movable iron core between the two poles of the permanent magnet.
When there is no current in the coil of the electromagnet, the movable core is attracted by the attraction of the two magnetic polar phases of the permanent magnet and remains stationary in the center; when there is current flowing through the coil, the movable core is magnetized and becomes a strip magnet.
In general, the molecules of air are neutral and uncharged. But after high voltage discharge, they become charged particles, which is called dissociation. If the dissociated air is vibrated by audio voltage, sound wave will be generated, which is the principle of ion loudspeaker.
In order to ionize, it is necessary to add 20MHz high frequency voltage and overlap audio signal voltage on it. The ion loudspeaker is composed of high frequency oscillation part, audio signal modulation part, discharge chamber and horn.
In the discharge chamber, a quartz rod with a diameter of 8 mm is cut in the center to form a quartz tube. One electrode is inserted into it, and the other electrode is wrapped outside the quartz tube in a cylindrical shape. Due to the silent discharge mode, only the needle electrode in the center has loss, so the central electrode can be replaced regularly.
The difference between ion loudspeakers and other loudspeakers is that there is no diaphragm, so the transient and high frequency characteristics are very good, but the structure is very complex.
7.Ultrasonic loudspeakers, ultrasonic loudspeakers, have just been developed in recent years and are entering the practical stage. The principle of this technology is: it does not use any traditional loudspeaker unit, but uses an ultrasonic generator to generate two specially processed ultrasonic beams. When the two beams act on the eardrum at the same time, the hearing can be generated due to the interaction.
8. Electrostatic loudspeakers (capacitive loudspeakers) electrostatic loudspeakers are loudspeakers that work by using the electrostatic force added to the capacitor plates. In terms of its structure, the electrostatic loudspeakers are also called capacitive loudspeakers because the positive and negative poles are opposite to each other.
It has two thick and hard plates as fixed plates, on which sound can be transmitted. The middle plate is made of thin and light material (such as aluminum film). Fix and tighten the diaphragm around and keep a certain distance from the fixed pole, even on the large diaphragm, it will not collide with the fixed pole.
There is a DC voltage between the two electrodes of the electrostatic loudspeaker. If the audio frequency voltage output by the amplifier is added between the two electrodes, it overlaps with the original output voltage to form an alternating pulsating voltage. The fluctuating voltage is generated by the change of attraction between the two poles, and the diaphragm vibrates and makes sound.
The advantages of the electrostatic loudspeaker are that the whole diaphragm vibrates in phase, the diaphragm is light, the distortion is small, it can replay the extremely clear sound, has the very good analytical power, the detail is clear, the sound is lifelike. Its disadvantages are low efficiency, high-voltage DC power supply is required, easy to dust, the diaphragm will increase distortion, not suitable for listening to rock and heavy metal music, the price is relatively expensive.
9.Air flow modulated loudspeaker (airflow loudspeaker) airflow modulated loudspeaker is a kind of loudspeaker which uses compressed air as energy and uses audio current to modulate airflow to produce sound. It consists of air chamber, modulation valve, horn and magnetic circuit. The compressed air flow is modulated by the external audio signal through the air chamber through the valve, so that the fluctuation of the air flow changes according to the external audio signal. At the same time, the modulated air flow is coupled with the horn to improve the efficiency of the system. Generally, it is mainly used as the sound source of high intensity noise environment test or long-distance broadcasting.
10. Piezoelectric loudspeakers are called piezoelectric loudspeakers, which use the converse piezoelectric effect of piezoelectric materials. Dielectric (such as quartz, potassium sodium tartrate and other crystals) polarize under pressure, resulting in potential difference between the two ends of the surface, which is called "piezoelectric effect". Its inverse effect, that is, the dielectric placed in the electric field will undergo elastic deformation, which is called "inverse piezoelectric effect" or "electrostriction".
The above classification is mainly based on the principle of phonation. According to the shape of diaphragm, the louder speaker can be divided into cone, flat plate, ball top, strip and sheet shape; according to the sound release frequency, it can be divided into bass speaker, mid tone speaker, high pitch speaker, full band speaker, etc.