The dynamic microphone is made by the principle of electromagnetic induction. It uses the coil to cut the magnetic line of induction in the magnetic field and converts the sound signal into an electric signal. Generally speaking, the effect is better. It is used in higher-end equipment, and it is used in good microphones. This kind of moving coil is more expensive.
The use of dynamic microphones is relatively simple, does not require polarized voltage, has stable performance, is firm and reliable, and is relatively inexpensive. It is still widely used in karaoke. But its transient response and high frequency characteristics are not as good as condenser microphones. Dynamic microphones usually have low noise, no need to feed power, easy to use, stable and reliable performance. The main features include:
1. Firm structure, stable performance, durable, low price; good frequency characteristics, flat amplitude-frequency characteristic curve in the frequency range of 50-15000Hz;
2. Good directivity;
3. No need for DC working voltage, easy to use and low noise.
Condenser microphones use changes in the size of capacitors to convert sound signals into electrical signals, which are also called electret microphones. This kind of microphone is relatively high-end. The capacitive type is small in size and has a better effect. It is sometimes called a microphone. The condenser microphone has two metal plates, one of which is coated with an electret film (mostly polyperfluoroethylene propylene) and grounded, and the other plate is connected to the gate of the field effect transistor, the gate and the source A diode is connected between the poles. When the electret diaphragm itself is charged, the surface charge is Q, and the inter-plate capacitance is C, then the ground voltage U=Q/C is generated on the pole head, when it is subjected to vibration or friction by airflow , Due to vibration changes the distance between the two plates, that is, the capacitance C changes, but the power Q does not change, it will cause a voltage change. The magnitude of the voltage change reflects the strength of the external sound pressure, and the frequency of this voltage change reflects The frequency of the outside sound, this is the working principle of electret microphone.
1. It can directly convert sound into electrical energy signal
2. Can show the characteristics of original sound reproduction
3. Has an extremely wide frequency response
4. Has ultra-high sensitivity
5. Fast transient response characteristics