The basic principle of Fleming's law from the left hand, put a wire with a current perpendicular to the magnetic field lines into the magnet poles and wires will interact with each other by both magnetic field and current moving in to a diaphragm attached to this line, with the current changes of diaphragm produced before and after exercise. At present, more than ninety percent of the cone monomers are designed with a moving coil.
A removable chopped iron piece (armature) can be erected in the middle of a U type magnet. When the current flows through the coil, the armature will be magnetized and magnetized to attract and repellate, and at the same time, it will drive the diaphragm movement. This design is cheap but not effective, so it is more used on the phone and small headphones.
Similar to the electromagnetic principle, however, the armature is doubled, while the two voice coil on the magnet is not symmetrical. When the signal current passes, the two armature will push each other to move for different magnetic flux. It is different from the electromagnetic field that the inductor can be regenerated at a lower frequency, but the efficiency is very low.
The basic principle is the law of Kulun (Coulomb), usually in plastic diaphragm and the processing perceptual materials aluminum vacuum vaporization electricity, two diaphragm face, which is a current when the high voltage is added another piece will induce a small current, with each other to attract and promote the air will be able to issue a rejection sound. Because of its light weight and small vibration dispersion, the electrostatic monomer is easy to get clear and transparent middle pitch, which has not been able to catch bass power, and its efficiency is not high. It is easy to gather dust with DC. At present, such as Martin-Logan and other manufacturers have successfully developed electrostatic and moving coil hybrid speakers, to solve the problem of static body bass deficiency, and the use of electrostatic on headphones is also very extensive.
The design of voice coil, which was first developed by Japanese SONY, is still the theme of moving coil. However, the cone basin diaphragm is changed into the honeycomb structure plane diaphragm, because the effect is very small, but the efficiency is also low.
Without the traditional design of the sound ring, the vibration film is made of very thin metal, and the current flows directly into the body to make it vibrate. Because its vibration film is a sound ring, the quality is very light, the transient response is excellent, and the high frequency response is good. However, the efficiency and low impedance of the ribbon trumpet are always a big challenge for the expansion machine, and Apogee can be represented. Another way is to have voice coil, but the voice coil is directly printed on plastic sheets, which can solve some problems of low impedance. Magnepang is the leader of such design.
To promote the work and the diaphragm air located at the bottom of the horn, because the sound transmission is not so diffusion efficiency is very high, but because of the shape and length of the horn will affect the tone, to replay the low frequency is not very easy, now mostly used in large PA system or the tweeter, Klipsch is the time-honored horn producers.
And in the modified design of ribbon Dr. Hale in 1973 developed, known as the Hale horn theory is very good, but very few users in Taiwan. Piezoelectricity is the design of making use of titanic acid isoparic electric material plus voltage to make it expand or shrink. The Pioneer has been improved piezoelectric design with high polymer to use on their treble monomer. Ion horn (Ion) uses high voltage discharge to make the air become a charged mass. After the AC voltage is applied, the free charged molecules will vibrate because of the vibration. At present, they can only be used for monomers above the high frequency. PHILPS has also developed active feedback trumpet (MFB), which has an active feedback circuit in the horn, which can greatly reduce the distortion.