Video: Condenser microphone
Just like the dynamic microphone, the condenser microphone – also known as the electrostatic or capacitor microphone – contains a membrane that vibrates on contact with the ambient air, but no coil adds to its weight.
It is therefore very responsive, even to high frequencies…
But it is also more fragile, and becomes saturated more quickly at high volumes.
Note also that it must be powered by an external energy source.
For these reasons, condenser microphones offer the best conversion quality but they are preferably used in a studio.
The principle underlying their functioning rests on the laws of electrostatics:
A thin, mobile membrane, made of a conducting material, is placed in front of a plaque, which is also a conductor.
This arrangement creates the two armatures of a plane condenser, also known as a plane capacitor.
The value of the electrical capacity – or capacitance – “C”, of this condenser, depends on the distance “e” that separates the two faces.
The voltage, measured at the condenser’s poles, is precisely proportional to the capacity.
We are therefore measuring an electrical value that is a faithful image of the mechanical deformation.