Based on the working principles of microphone capsules, the main types available in the market are: Dynamic Microphone, Condenser Microphone, Electret Condenser Microphone, and MEMS Microphone.
Microphone Capsule Types
1. Dynamic Microphone
Working principle: The basic structure includes a coil, diaphragm, and permanent magnet. When sound waves enter the microphone, the diaphragm vibrates due to the sound pressure. The coil attached to the diaphragm moves within the magnetic field, generating an induced current according to Faraday's law of electromagnetic induction.
Characteristics: Dynamic microphones contain magnets and coils, making them less portable, less sensitive, and with poorer high and low-frequency response. However, they produce a warm sound, suitable for capturing vocals, and are commonly used in karaoke settings.
2. Condenser Microphone
Working principle: It generates voltage changes based on the distance variation between two capacitor plates. When sound waves enter the microphone, the diaphragm vibrates, changing the distance between the diaphragm and the backplate, resulting in a change in capacitance and, subsequently, the charge amount (Q = C * V).
Characteristics: High sensitivity, commonly used for high-quality recording in consumer electronics and recording studios.
3. Electret Condenser Microphone
Working principle: Uses electret material that retains a permanent charge, eliminating the need for continuous power supply (unless an internal amplifier circuit is present).
Characteristics: Mature technology and low cost. However, it is bulky, not suitable for SMT, may have signal attenuation due to long leads, and has inconsistent sensitivity and stability.
4. MEMS Microphone
Working principle: Also known as microphone chips or silicon microphones, MEMS microphones often integrate a preamplifier, and some even include an analog-to-digital converter to directly output digital signals.
Characteristics: Directly converts sound into electrical signals, featuring high sensitivity, durability, impact resistance, compact size, light weight, and high-temperature solderability.
