This kind of microphone is the most common, because it is cheap, compact, and the effect is not bad. Sometimes it is also called microphone. The specific principle is that on a layer of special material, there is an electric charge, which is not easy to release. When people speak, the charged film vibrates with them. Because of the constant charge on it, the voltage will also change according to q = Cu. In this way, the sound signal will be converted into an electrical signal. This electrical signal is generally added to a field effect transistor inside the microphone to amplify the signal. When connecting to the circuit, you should pay attention to its correctness Connection. In addition, it is piezoelectric and other types. Now piezoelectric microphones are also commonly used in some low-end devices.
　　The core component of the condenser microphone is the stage head, which is composed of two pieces of metal film; when the sound wave causes its vibration, the different spacing of the metal film causes the different capacitance, which produces the current. Condenser microphones generally need to use 48V phantom power supply, as well as microphone amplification equipment, or mixer to work.
　　Condenser microphone is one of the oldest microphone types, which can be traced back to the early 20th century. Compared with other types of microphones, the mechanical structure of condenser microphones is the simplest. It is mainly to post a thin conductive diaphragm on a metal sheet called back plate, and use this structure to form a simple capacitor. Then, an external voltage source (usually phantom power supply, but most condenser microphones also have their own power supply device) is used to supply power to the capacitor. When the sound pressure acts on the diaphragm, the diaphragm will make a variety of slight vibration with the waveform, and then the vibration will cause the change of output voltage through the change of capacitance, which constitutes the output signal of the microphone. In fact, condenser microphones can be divided into several types, but their basic working principles are the same. Currently, the most popular condenser microphone is Neumann's U87.