Microphones Flashcards
What type of energy to microphones convert?
Microphones convert acoustical energy (sound waves) into electrical energy (the audio signal)
What is the one part of a microphone that all types have?
A diaphragm
What is the diaphragm of a microphone?l and what does it do?
The diaphragm is a thin piece of material which vibrates when it is struck by a sound wave. When the diaphragm vibrates it caused other components in the microphone to vibrate and the vibrations are converted into electrical energy
What is mic level?
The electrical current generated by a microphone measure in millivolts
What is line level?
Line level is the standard signal strength used by audio processing equipment
What are the ways that mic level can by amplified to line level?
Some mics have a built in amplifier
The mic can be fed through a small amp
Sound mixers have small amps in each channel
Audio signal can be sent to a specialised amp
What are the characteristics of a condenser microphone?
Require power from a battery or external source (phantom power)
Stronger signal
More sensitive to higher frequencies
Prone to overloaded from high levels of SPL
Fragile in use
How does a condenser microphone work?
A capacitor has two plates with a voltage between them. The diaphragm vibrates when struck by sound waves changing the distance between the two plates changing the capacitance.
Plates closer together - capacitance increases and a charge current occurs
Plates further apart - capacitance decreases and discharge current occurs
What are the characteristics of a dynamic microphone?
Versatile Idea general purpose use Sturdy Resilient to rough handling Better suited to high levels of SPL No internal amplifier Do not require batteries or external power
How does a dynamic microphone work?
The diaphragm, attached to a coil of wire vibrates in response to sound waves. He could moves backwards and forwards past a magnet which creates a current in the coil which is channeled from the microphone to a mixer via a XLR cable
What does omnidirectional mean and what are it’s uses?
Captures sound from all directions:
Capturing ambient noise
Where sound is coming from all directions
Where sound source is moving
Lack focus and bleed can be worse
What does cardioid mean and what are it’s uses?
Heart shaped, picks up mostly from the bit but slightly at the sides:
Emphasising sound from the direction the mic is pointed
What does hyper cardioid mean and what are it’s uses?
Eliminated most sound from the sides and back.
Used for isolating sound from a subject or direction where there is a lot of noise or the sound is at a distance
What does bi directional mean and what are it’s uses?
Picks up sound equally from two opposite directions
Traditionally used to record two vocalists facing each other
