The classification and difference of microphones
Although strictly speaking, microphones (scientific name microphones) can be divided into many categories according to different working methods, but nowadays they are widely used in professional and amateur recording situations, mainly dynamic microphones and condenser microphones (Condenser).
We know that the microphone works by changing the air pressure caused by the diaphragm to induce sound waves, which is similar to the "work" principle of our ears. The diaphragm of the dynamic microphone (equivalent to our eardrum) is located in the annular gap between a cylindrical magnet and a soft iron. The diaphragm is connected with a movable coil suspended between the two magnetic poles. Call it "voice coil." The sonic vibration diaphragm causes the voice coil to cut magnetic lines of force in the gap in motion, thereby inducing current and outputting.
The advantages of the dynamic microphone are simple structure, low price, stable operation, sturdy and durable, long life, and are widely used in various recording occasions. However, due to its low sensitivity, the frequency response is not wide enough (the best state is 40Hz ~ 16kHz, and the average hearing limit of the human ear is about 20Hz ~ 20kHz), so if you use a dynamic microphone to record some frequencies, the dynamics are wider. Sound sources with large and overtone components (such as an orchestral ensemble) are a bit overwhelming.
In a professional studio, the sound engineer usually uses more condenser microphones. The full name of the condenser microphone is the "static capacity change type microphone". At its core is a capacitor consisting of a very lightweight movable diaphragm plate and a fixed plate. This device is called a "pole" or "capacitor box". When the pole is applied with a polarization voltage, an electric charge is generated on the two plates. The sonic vibration diaphragm (that is, the moving plate) changes the charge and eventually generates a voltage across the load resistor to form an audio signal.
Capacitive microphones have high sensitivity and wide frequency response, ranging from 20 Hz to 20 kHz or more, which can meet the needs of most professional recordings. Its shortcomings are sensitive to environmental noise, the diaphragm is also fragile, and its life is short, so it is not suitable for outdoor use.
Since the pole of a condenser microphone must be polarized to operate, it is necessary to supply power to the condenser microphone. Think about it, if every microphone has to be connected to a power cord and an audio cable, how troublesome it can be. In order to minimize the connection, people have come up with the "Phantom Power" approach. The so-called "phantom power supply" refers to both the audio signal current and the DC power supply voltage in the same cable. In this way, we only need to connect one audio cable to get the polarization voltage and audio signal at the same time.
Most large diaphragm condenser microphones (such as takstar SM-1A, SM-1B, etc.) require 48V phantom power, so most professional mixers also have built-in 48V phantom power. However, some types of condenser microphones also require special phantom power supply voltages, such as takstar GN-260, GN-270, etc., which can work from 9V to 52V.