Introduction to the working principle of six kinds of speakers

1、Magnetic loudspeaker (tongue)

Magnetic speaker, also known as the tongue of the tongue is. In the magnetic loudspeaker structure, permanent between the poles of a magnet has a movable iron core of the electromagnet, when no current in the coil of the electromagnet, permanent magnets, magnetic poles level attraction attraction by the movable iron core, in the central remain stationary; when in the current flowing through the coil, a movable iron core is magnetized and become a bar magnet.

With the change of the direction of the current, the polarity of the bar magnet changes, so that the movable core can rotate around the fulcrum, the vibration of the movable core is transmitted by the cantilever to the vibrating film (paper basin).

2、Ion speaker

In general, the molecular weight of the air is neutral, and is not charged. But after high pressure discharge, it becomes a charged particle, which is called free. The principle of a sound wave, which is the principle of the ion speakers, is generated by the use of the free air in the audio frequency.

In order to be ionized, the high frequency voltage of 20MHz is to be added, and the signal voltage is overlapped on it. The speaker by high frequency oscillation part, ion modulated audio signal part, discharge cavity and horn composition. Discharge cavity with the diameter of 8mm quartz rod in the center hole, into a quartz tube, an electrode inserted in, another electrode is cylinder shaped sleeve in a quartz tube outside, due to the adoption of the silent discharge form, only the center of the needle electrode lossy and can be replaced regularly center electrode.

The difference between the ion speakers and other speakers is that there is no film, so the transient and high frequency characteristics are good, but the structure is very complex.

3、Ultrasonic speaker

The so-called ultrasonic speaker, is a few years ago just developed, is entering the practical stage of the ultrasonic sound technology.

The ultrasound sound technology principle: it does not use any of the traditional form of the speaker unit, but the use of ultrasonic generator produce two beams through special processing of the ultrasound beam, when the two beams at the same time in the human ear tympanic membrane can generate hearing because of the interaction.

We know that there is only one beam to the sound of the drum when it is not heard. Because the ultrasonic speed is very strong, can control the directivity, the intersection of the two beams can point to form a small range of sound area, when people are in the area of the region, you can hear the sound, and people's ears once left the area will not hear.

Using this feature, now some of the top luxury cars start equipment set of the ultrasonic sound system, on a per seat forms a listening area, so you can let each of the passengers of their choice like enjoy the content, and mutual and not produced any interference, also won't affect a passenger conversations.

4、Electrostatic speaker (capacitive speaker)

Electrostatic loudspeaker is a loudspeaker with added to the capacitor plate on the static electricity and work, on the structure, a capacitor like from the positive and negative electrodes are opposite, so it is also called as condenser loudspeaker.

Electrostatic speakers have two thick and hard materials as a fixed plate, the plate can be made through the sound, the middle of a plate with a thin and light material for vibrating film (such as aluminum film). Will diaphragm fixed around, taut and with fixed pole to maintain a considerable distance, even in the large diaphragm on, nor cause the collision with the fixed pole.

The original DC voltage of the two electrode of an electrostatic speaker (referred to as bias). If the two electrodes are coupled with the output voltage of the amplifier, the output voltage is overlapped to form an alternating current, which is caused by the change of the attraction of the poles.

The advantages of the electrostatic speaker is the whole vibration film in phase vibration, the vibration film is light, distortion is small, it can playback is very crisp sound, has a very good analytical, detail, sound fidelity. Its disadvantages are low efficiency, high voltage DC power supply, easy to vacuum, the vibration film will increase the distortion will increase, not suitable for listening to rock, heavy metal music, the price is relatively expensive some.

5、Air modulated speaker (airflow speaker)

Air current modulation of the speaker is the use of compressed air to make energy, the use of audio frequency current modulation of the voice of the speaker. It consists of a gas chamber, valve, horn and magnetic modulation. Flow of compressed air from an air chamber through the valve in, by the external audio signal modulation, airflow fluctuation according to the external audio signal and change, at the same time be modulated airflow coupled via the horn, to improve the system efficiency.

Generally used to do high intensity noise environment test of sound source or radio, etc..

6、Piezoelectric speaker

A speaker called a piezoelectric speaker, which works with the converse piezoelectric effect of the piezoelectric material. Dielectric (such as quartz and sodium potassium tartrate crystal) in the pressure under the action of polarization, the potential difference between both ends of the surface, we call it pressure electric effect. Its inverse effect, that is, in the electric field of the dielectric will occur elastic deformation, known as the inverse piezoelectric effect or.

Compared with the electric type loudspeaker, the piezoelectric speaker does not need the magnetic circuit, and compared with the static electricity, the structure is simple and the price is cheap, but the disadvantage is that the distortion is large and the work is not stable.