The type and technical index of the moving-coil microphone
The type and detection method of microphone is a device that converts sound energy into an audio Telecom number,also called a microphone.The types of microphone are also many, the most widely used is the moving-coil simple and electret condenser microphone.The symbol for the microphone is " BM ".
The type and technical index of the moving-coil microphone
moving-coil microphone consists of a permanent magnet,a sound film,and a voice coil,the voice coil is located in the gap of the permanent magnet and is stuck together with the sound film.When there is a sound,the sound wave excites the vibration of the sound film,drives the voice coil to make the cutting magnetic force line to move and produces the audio frequency induction voltage,so as to realize the acoustoelectric conversion.The main technical parameters of the movable coil type simple tube are frequency response,sensitivity,output impedance,directivity and so on.The frequency response range of the moving-coil microphone is obviously wider and the better,but the wider the frequency response range,the higher the price.The frequency response range of the ordinary moving-coil microphone is 100 ~ 10000Hz,and the frequency response range of the microphone with good quality can reach 20 ~ 20000Hz.
The sensitivity of the moving-coil microphone refers to the ability of the microphone to convert the sound signal into a voltage signal,which is expressed by the number of millivolts per Pascal sound pressure,its unit is mV / Pa.The sensitivity of the microphone is also commonly expressed in decibels ( dB ).In general,the higher the microphone sensitivity,the better the quality of the microphone.The output impedance of the moving-coil microphone is of high impedance and low impedance.The output impedance of the high impedance microphone is 20kilo-ohm,and the output impedance of the low resistance microphone is 6002,which is used in conjunction with the transmission impedance of the amplifier.Generally,after purchasing the amplifier,the corresponding microphone is purchased according to the impedance of the amplifier.
The directivity of the moving-coil microphone refers to the sensitivity of the microphone and the characteristics of the acoustic direction.The directivity of the microphone is designed according to the needs,and it is divided into all-directional microphone,one-way directional microphone,two-way directional microphone and near-speaking microphone. The all-directional microphone has the same sensitivity as the sound from all sides.The sensitivity of the one-way directional microphone is significantly higher than that of the back and side.Two-way directional microphone has the same sensitivity on the front and back,and the sensitivity on both sides is relatively low.Near speaking,the microphone only has a high sensitivity to the sound near the microphone,which is not sensitive to the distant environment noise,which is mostly used by singers on stage and singing.
the detection of the moving coil microphone is mainly based on the electric barrier of the multimeter,secondary coil and coil.First,I use two stylus to touch the two leads of Jane,and the microphone should give out a clear"Kaka"sound.If it is silent,it means that there is a fault in the speech,and the various coils of the microphone should be further checked.