How microphones work Flashcards
What is a microphone?
A transducer that converts between types of energy
The mic’s capsule contains the transducer.
How do dynamic microphones operate?
They use electromagnetic induction with a movable coil attached to a diaphragm in a magnetic field.
What happens when sound hits the diaphragm of a dynamic microphone?
The diaphragm vibrates, moving the coil through the magnetic field and inducing a varying electrical current proportional to air pressure changes.
What are the advantages of dynamic microphones?
Inexpensive, robust, withstand high SPL, resistant to moisture, do not require phantom power, suitable for live use.
What is a disadvantage of dynamic microphones compared to condenser microphones?
They do not capture high frequencies as well.
What is a characteristic of the diaphragm in dynamic microphones?
It is heavy and introduces a form of acoustic compression.
What is the transient response of dynamic microphones compared to condenser microphones?
Much slower than for a condenser microphone.
What do condenser microphones consist of?
Two capacitor plates.
How does sound affect the plates in a condenser microphone?
Sound causes one plate to vibrate.
What powers a condenser microphone?
Phantom power or a battery.
What happens when the diaphragm in a condenser microphone moves?
It causes a change in capacitance as the gap between plates changes, resulting in a current flow.
What are the advantages of condenser microphones?
Sensitive, capture quiet sounds well, flat and accurate frequency response, wide frequency range, used for most studio work.
How does the signal from a condenser microphone compare to that from a dynamic microphone?
Brighter due to fast transient response and higher output volume, providing a good signal to noise ratio.
Are ribbon microphones commonly used today?
Less commonly than dynamic or condenser microphones.
How do ribbon microphones operate?
Like dynamics, using electromagnetic induction.
What is an advantage of ribbon microphones over dynamic microphones?
Able to follow sound wave movements more accurately due to a lighter ribbon.
What is a disadvantage of ribbon microphones?
Fragile, often very expensive, and can be damaged by phantom power.
