Classification Of Earphones

1. Moving coil type

Dynamic coil earphones are the most common and common earphones. Its driving unit is basically a small dynamic coil speaker. The voice coil in the permanent magnetic field drives the diaphragm connected to it to vibrate. Dynamic earphones are highly efficient, most of which can be driven by the earphone output on the audio system, and are reliable and durable. Generally speaking, the larger the diameter of the driving unit, the better the performance of the earphone. In consumer earphones, the maximum diameter of the driving unit is 70mm, which is generally flagship earphones.

2. Movable iron type

It is an earphone that is transmitted to the center point of a micro diaphragm through a precision connecting rod to generate vibration and sound. Moving iron earphones can be easily put into the ear canal because the unit size is much smaller. This method effectively reduces the area of the in ear part and can be inserted into the deeper ear canal part. The geometric structure of the ear canal is much simpler than that of the auricle, and it belongs to the quasi circular shape. Therefore, a soft silicone sleeve can play a good sound insulation and leakage prevention effect compared with the traditional earplug.

3. Ring iron mixing

The ring iron earphone is a kind of earphone driven by the mixed driving of the moving coil and the 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 electro acoustic conversion efficiency and light vibration body. Therefore, it has high sensitivity and good transient performance, highlighting the music dynamics and transient details that are difficult to be expressed by the original moving coil. The low frequency and medium frequency are naturally presented by the moving coil unit, giving play to the advantages of good low frequency extension of the moving coil, fullness of the medium frequency and natural transition. 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.

4. 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, like a printed circuit board, can evenly distribute the driving force. 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 constant 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 dynamic earphone and is not easy to drive.

5. Electrostatic type

Electrostatic earphones have a light and thin diaphragm, which is polarized by high DC voltage. The electric energy required for polarization is converted by AC power, 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. The electrostatic earphone is expensive and is not easy to drive. The sound pressure level it can reach is not as large as that of the dynamic earphone. However, it has a fast reaction speed and can reproduce various small details with extremely low distortion.

6. Electret

Electret earphones are also called fixed electrostatic earphones. The diaphragm itself is polarized or the electrostatic field emitted by the polarized material outside the diaphragm is polarized, 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.

7. Wireless Cordless

They are composed of two parts, a signal transmitter and an earphone (usually a moving coil type) with a signal receiving and amplifying device. The transmitter is connected to the signal source, and the front stage or headphone amplifier can also be connected in front of the transmitter to improve the sound quality and adjust the sound color.