1. This is related to the sensitivity of the microphone. The sensitivity may be too high, but in fact sometimes high sensitivity is necessary. In this case, noise should be minimized during recording.
2. It is more likely that the electromagnetic interference experienced by the microphone is too great. Since capacitive microphones have virtually no internal resistance, their connections are very susceptible to electromagnetic interference. Therefore, capacitive microphones generally use shielded connections to reduce interference.
You can determine which situation this is by completely blocking the microphone head, for example by pressing it on a rubber pad. If the noise is still relatively loud, it must be electromagnetic interference and should therefore be replaced with. a point shield connection.
Connect an ap resistorparallel to the microphone (depending on the specific situation of the microphone, you can try to use 10K or more, or just get a 100K potentiometer and manually adjust the resistance to the appropriate value), and connect it in parallel . Resistors will reduce sensitivity to a certain extent and at the same time filter out some electromagnetic interference.
Detailed information:
Working principle of condenser microphone:
The sound pickup principle of condenser microphone consists of to use an extremely thin microphone. gold plated The membrane, as the pole of the capacitor, has another fixed electrode separated by a few tenths of a millimeter. This forms a capacitor of several farads P. The membrane electrode vibrates with the sound waves, causing a change in capacitance. forming an electrical signal. Since this capacity is only a few Pfarads, the capacitance of the membrane electrode changes, its internal resistance is extremely high, reaching the level of G ohm.
So you need a circuit to convert this G-ohm impedance into a universal impedance of around 600 ohms. This circuit, also called a "pre-amplification circuit", is usually integrated inside the condenser microphone and requires. “phantom” power supply to power the circuit.