Speaker Classification

Piezoelectric Speaker : using the inverse piezoelectric effect of piezoelectric materials and working speaker called a piezoelectric speaker . A dielectric ( such as quartz, crystalline sodium potassium tartrate , etc. ) occurs under pressure so that the Multimedia Speaker polarization potential difference between the both end surfaces of the phenomenon called " piezoelectric effect ." Its inverse effect, that is placed in the electric field of the dielectric elastic deformation may occur , known as " reverse piezoelectric effect" or " electrostrictive ."
Piezoelectric speakers compared with electrodynamic loudspeaker does not require magnetic and electrostatic speakers do not need to bias compared to a simple , cheap , big drawback is distorted and unstable.
Ion Speaker: In normal state , the molecular weight of the neutral atmosphere , it is not charged . But after a high-voltage discharge after becoming charged particles , a phenomenon known as ionized . The ionized air vibrations using an audio voltage , the resulting sound waves , which is the principle of ion speaker .
For ionization , it is necessary to 20MHz high frequency voltage , the piezoelectric overlapping audio signals thereon . Seen by the high-frequency oscillation section ion speaker , an Multimedia Speaker audio signal modulating section , the discharge chamber and horn components.
Discharge chamber using quartz rod diameter of 8mm hole in the center , open into a quartz tube , which is inserted an electrode and another electrode , the cylindrical sleeve in a quartz tube outside, thanks to the silent discharge form, only the center needle electrodes loss center electrode can be replaced periodically . Ion speaker that differs from other speakers at no diaphragm, so the transient characteristics and frequency characteristics are good, but the structure is too complex.
Fire Speaker : When the air and gas flame burning through the electrode , the electrode plus a DC voltage and high-frequency signals , fire and sound by audio signal modulation . Flame almost massless , dynamic sound excellent . But it has a fatal drawback : unsafe , inconvenient.
Airflow modulation Speaker : also known as airflow speaker. It is the use of compressed air as an energy source , the use of current modulation airflow sound audio speakers. It consists of the chamber , a modulation valve , horn and magnetic components. Compressed air from the air chamber through the valve , the external audio signal is modulated by that flow fluctuations vary according to the applied audio signal while being modulated by the air horn coupled to improve the efficiency of the system. It is mainly used as source or remote radio noise environments such as high-strength tests .