Test 2 Flashcards
(33 cards)
Who invented the first mic? When? How does it work?
Berliner, 1877, intended for telephones. An electric acoustic device that converts to acoustical
Who invented the first capacitance mic? When? How does it work?
E.C Wente, 1916, 1st condensor. 2 thin plates, 1 move, 1 is fixed with charge applied. The acoustic pressure changes the capacitance
Who invented the first moving coil mic? When? How does it work?
E.C Wente, 1928, better bandwidth. It moves through the magnetic field in response to the sound waves hitting the diaphragm, and it produces voltage proportional to sound
Who invented the ribbon mic? When? How does it work?
Harry Olsen, 1932. It uses a medal ribbon attached to a fixed magnet, ribbon then vibrates from the pressure of the sound waves so voltage is generated
Phantom Power
Convenient power source for condenser microphones
What does linear mean?
Having an output that varies in direct proportion to the input
2 switches that exist on some mics? Explain
Bass Roll Off- reduces less frequency
Pad- cuts the volume
Polar pattern
A microphones sensitivity with respect to direction and frequency
3 different polar patterns
Omni- all around
Bi directional- front and back
Cardiod- front (heart shaped)
Microphones frequency response
Range of frequency a mic can produce
3 types of stereo mixing
Spaced Pair- 2 identical mics spaced 3-30ft from each other
Deca Tree- uses 3 omni mics, placed in T 8-20in apart
Coincident (X/Y)- 2 identical mics, capsules aligned 90-135 degrees
Pros and Cons of close and distant microphone techniques
Distant- >3ft from source, high probability of phase cancellations, room tone/ambiance
Close-<3ft from source, adds presence and gives isolation to the sound, few phase cancellations
ORTF
2 identical mics, near coincident that are at an angle of 110 degrees
M/S
mid-side
3:1 Rule
Each microphone must be at least 3 times farther apart from the source
On axis vs. off axis
On- talking directly in front of the mic
Off- off center of the mic
What part of the mic give its sound?
The element
3 types of loudspeakers
Moving coil (most common) Ribbon Electrostatic
Frequency response
Measure of an audio systems ability to reproduce a range of frequencies with the same loudness
Distortion
Signal in a reproduced sound that wasn’t part of the original
Polar Response
How a loudspeaker focuses sound at a listening position
Far field vs. Near field
Far- larger and full range, but in wall and several feet from the listener
Near-maller and limited range, set on stands and console bridges, near listener
Headphone Monitoring
Eliminates influence of room acoustics on what you hear
High vs. Low frequencies
Low is larger and travels further, high is opposite
