Condenser vs Dynamic Microphone
Condenser microphone and dynamic microphone are two types of microphones, which are commonly used. Dynamic microphones are made based on the electromagnetic induction whereas condenser microphones are based on the operation of a capacitor (condenser). Both of these devices are very important in fields such as audio engineering, acoustics, data acquisition, communication technology, music industry and various other fields. In this article, we are going to discuss what condenser microphone and dynamic microphone are, their operation and the operation principles behind these devices, and finally the difference between condenser microphone and dynamic microphone.
A condenser microphone consists of a capacitor with a variable capacitance. The term “condenser” is due to the historical usage of the term condenser to identify the device known as the capacitor. A capacitor is a device made out of two metal plates kept apart by a dielectric medium such as air, paper or graphite. The capacitance of a capacitor depends on the area of the metal plates, the distance between metal plates and the dielectric medium between the plates. In a condenser microphone, the capacitor is placed so that when a sound hits one of the capacitor plates, the distance between the plates get smaller, thus increasing the capacitance of the capacitor. The capacitor is initially biased with a fixed charge (say Q). The variation of the capacitance changes the voltage between the two nodes of the capacitor according to the equation Q = C V where Q is the charge inside the capacitor, C is the capacitance of the capacitor and V is the voltage across the capacitor nodes.
A dynamic microphone is a device that is based on electromagnetic induction. When a closed conducting loop is placed inside a magnetic field, a change of magnetic flux through the loop causes an electromotive force. This electromotive force produces a current which in turn will create a magnetic field opposing the initial change of magnetic fields. The diaphragm of the dynamic microphone is connected to such a coil. This will cause a variable current according to the oscillation of the diaphragm. The oscillation of the diaphragm is characteristic to the sound wave incident on it. This is exactly the opposite operation of a magnetic speaker.
What is the difference between Condenser Microphone and Dynamic Microphone?
• A condenser microphone is based on the theory of capacitance of parallel metal plates whereas the dynamic microphone is based on the theory of electromagnetic induction.
• The condenser microphone requires an external battery to keep the biasing of the capacitor, but the dynamic microphone does not require such a power source.
• The gain of dynamic microphones is higher than the gain of condenser microphones.
• Condenser microphones operate on a voltage signal whereas dynamic microphones operate on a current signal.