How Do The Condenser Mics Work?
A condenser means a capacitor, which is an electronic component that stores energy in the form of an electrostatic field. Actually, the term condenser itself is rarely used but has become a name for this type of microphone, which uses a capacitor to convert acoustic energy into electric current.
Condenser microphones require power from batteries or other external sources. The resulting audio signal is stronger than a dynamic microphone. Because they tend to be more sensitive and responsive than dynamic microphones, condenser microphones are better suited for capturing small details in sound.
On the other hand, this microphone is not ideal for working at high volumes because its sensitivity level is prone to distortion, in other words, it is less able to accept SPL that is too high. So pay attention to the technical data of your condenser microphone to know the limitations. But, today’s condenser microphones have a high maximum input SPL of up to 130 dB!
How Condenser Microphones Work
A capacitor consists of two plates with a voltage between them. In a condenser mic, one of the plates is made of a very light material and functions as a diaphragm. When exposed to sound waves, this diaphragm plate will vibrate causing a change in the distance between the two plates, causing a change in capacitance. More clearly, when the two plates are close to each other, the capacitance will increase and there will be an increase in current. When the two plates move away from each other, the capacitance decreases, and the current discharges. This happens fast, or in other words, its vibrating follows the sound waves that come from our mouths or instruments.
Condenser capsule diagram (press gradient)
In order for the capacitor to work, it needs an electric voltage. The electricity can come from the battery inside the mic or from another external source (phantom power). The phantom power is standardized at 48 volts by Neumann, a microphone company from Germany a long time ago.
Electret Condenser Microphone
Electret condenser microphones use special capacitors that already have a permanent voltage that is attached to the production process. It’s like a permanent magnet so it doesn’t need any external power to work.
However, good electret condenser mics usually come with a pre-amplifier that still requires power to run. just like the SEM-02, it comes with an XLR dongle to pre-amplify the audio signal. However, SEM-02 does not always need phantom power when paired with a wireless transmitter or your smartphone. The reason is that the devices like a wireless transmitter and smartphone mic input have a plugin power to feed some current to the electret capsule in order to work.
As you can see, the principle of electret and press gradient is almost identical. Two of them used to be called condenser mics because used the difference in capacitance to create the audio signal.
So that is how the condenser mic works.
Hopefully, you get the idea now.
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