The types of microphones

There are two types of microphones are popular used, they are “Dynamic type” & “Electret condenser type”. Below is the description of the two types of microphones:

1. Dynamic type of microphone

The construction of the microphone is as below sectional drawing. The coil (1) sticks on a mylar(2), on speaking, the sound will vibrate the mylar and move the coil up and down. As the magnets (3)&(4) form a magnetic field and be surrounded by a plastic case(5), when the mylar and coil move up and down, they will result voltage to transfer sound into electric signal.

As the Dynamic microphone effects by moving the mylar and coil, it can not make instant reaction of sound but to cause harmonic distortion. The kind of harmonic distortion never cause bad influence in sound quality, but results a tender sound performance. Therefore, the Dynamic microphone is suitable for singing.

2. Electret condenser microphone

The construction of the microphone is as below sectional drawing. There is a 0.1mm gap between a mylar(1) (charged with static electricity) and a back electrode pad(3) by a washer(3). When the mylar feels the vibration of sound, it will cause electric capacity change with the back electrode pad, then transfer it to the FET(4) for electric signal. The FET is fixed on a PCB(5), and the signal will transfer from the two solder points(7) under the PCB to cable. A whole element is surrounded by an aluminum case.

The features of the electret condenser microphone is :

1. The size of the element is very small under Ø 9mm.

2. The microphone works at 1.5 – 9V voltage.

3. The microphone makes instant reaction of sound, with little distortion and higher sensitivity than dynamic microphone. It is suitable for recording used.