Moving coil type
Dynamic earphone is the most common and common earphone. Its driving unit is basically a small dynamic loudspeaker. The diaphragm connected to it is driven by the voice coil in the permanent magnetic field. Dynamic earphones have high efficiency. Most of them can be driven by the earphone output on the sound, and are reliable and durable. Generally speaking, the larger the diameter of the driving unit, the better the performance of the earphone. At present, the maximum diameter of the driving unit in consumer earphones is 70mm, which is generally flagship earphone.
Moving iron type
It is an earphone that transmits to the center point of a micro diaphragm through a precision connecting rod to produce vibration and sound. Moving iron earphones can be easily put into the ear canal because the unit is much smaller. This approach effectively reduces the area of the ear and can be put into the deeper part of the ear canal. The geometric structure of the ear canal is much simpler than that of the auricle, which belongs to quasi circle, so a soft silicone sleeve can play a good sound insulation and leak proof effect compared with the traditional earplugs.
Ring iron mixing
The coil iron earphone is a kind of earphone driven by the moving coil and moving iron. It has the structure of single moving coil + single moving iron and single moving coil + double moving iron. The advantages of the moving iron unit are high electroacoustic conversion efficiency and light vibrating body. Therefore, it has high sensitivity and good transient performance, highlighting the dynamic and instantaneous details of music that the original moving coil is difficult to show. The low frequency and medium frequency are naturally presented by the moving coil unit, giving full play to the advantages of deep diving of the moving coil low frequency and clear and natural transition of the medium frequency. The advantages and functions of the moving iron unit mainly undertake and supplement the high-frequency attenuation section of the moving coil. Starting from the frequency division point of 6KHz, the moving iron unit is responsible for the high-frequency and extends the high-frequency range to 30kHz.
Isomagnetic type
The driver of an isomagnetic earphone is similar to a reduced flat speaker. It embeds a flat voice coil into a thin diaphragm, which can evenly distribute the driving force like a printed circuit board. The magnets are concentrated on one or both sides of the diaphragm (push-pull type), and the diaphragm vibrates in the magnetic field formed by it. The equal magnet earphone diaphragm is not as light as the electrostatic earphone diaphragm, but it has the same large vibration area and similar sound quality. It is not as efficient as the moving coil earphone and is not easy to drive.
Electrostatic
Electrostatic earphones have light and thin diaphragm, which is polarized by high DC voltage. The electric energy required for polarization is converted by AC, and battery power is also available. The diaphragm is suspended in the electrostatic field formed by two fixed metal plates (stators). The electrostatic earphone must use a special amplifier to convert the audio signal into a voltage signal of hundreds of volts. Driven, the sound pressure level it can reach is not as large as that of the moving coil earphone, but it has fast response speed, can replay all kinds of small details, and the distortion is very low.
Electret
Electret earphones are also called fixed electrostatic earphones. Its diaphragm itself is polarized or polarized by the electrostatic field emitted by the polarized material outside the diaphragm, and no special equipment is required to provide polarization voltage. Electret earphones have most of the characteristics of electrostatic earphones, but the electret will gradually depolarize and need to be replaced. Its service life is about 5-10 years.
Wireless Cordless
Wireless noise reduction headset
They consist of two parts, a signal transmitter and an earphone with a signal receiving and amplification device (usually dynamic). The transmitter is connected with the signal source, or the front stage or headphone amplifier can be connected in front of the transmitter to improve the sound quality and adjust the sound color.
Wireless headphones generally refer to the headphone system that transmits signals by infrared, and cordless headphones refer to the headphone system that transmits signals by radio waves. The working frequency of infrared earphone ranges from several kHz to several MHz, and the effective distance is about 10 meters. The earphone should be within the visual range; The working frequencies of radio earphones are VHF 130mhz-200mhz and UHF 450 mhz-900mhz. Most cordless earphones work in UHF, with a transmission range of 100m and can bypass obstacles. Two or more pairs of wireless / cordless headphones may interfere with each other, so it is best to select a variety with multiple operating frequencies when selecting them. For cordless headphones, the interference may be less when working on UHF than on VHF. Both headphones have background noise, and the higher grade models adopt noise reduction technology. It should also be noted that the service time of wireless / cordless headset battery should not be less than 8 hours.
Today's more advanced wireless headphones adopt Bluetooth 3.0 transmission with aptx technology, which can provide advanced and CD like audio through Bluetooth.