s - change one form of energy into another (sound waves to electricity)
1.
Hand held 6. Lavaliere
(interviews)
2.
Boom
(discreet, on-camera)
7. Shotgun
(overhead studio) (mounted on video camera)
3.
Headset
(sportscaster)
8. Body microphones
(theatre)
4.
Stand mikes 9. Desk microphones
(stage - perform.) (podium or announcers)
5. Parabolic
(sports)
10. Boundary
(room coverage)
1. Moving coil (dynamic, durable),
2. Ribbon (sensitive, warm, pressure gradient)
3. Condenser (capacitor, battery or Phantom powered)
A capacitor is an electrical device used for storing electric charge. The basic design consists of two parallel conducting plates separated by an insulating layer called a dielectric.
1. Omni (no ports, 360 degree coverage)
2. Unidirectional or Cardioid (has ports, 180 degree coverage) rejects sound from rear & sides; isometric pressure from both sides cancels out sound
3. Bi-directional (90 degree coverage on either side)
4. Line gradient (shotgun mic. - directional)

The range of human hearing extends from 20Hz-20kHz.
Frequency, the rate at which sound vibrates, is used to express this range, measured in Hz, or cycles-per-second.
Sound pressure is measures in dB's (decibels)
20Hz - 60Hz Very low (elephants can hear)
60Hz - 500Hz Instrument's fundamental notes
500Hz - 2.5kHz Midrange (in excess fatigues the ear)
2.5kHz - 6kHz (boost @ 5kHz brightens sound)
6kHz - 15kHz contains harmonics & overtones
INVERSE SQUARE LAW:
Doubling the distance, quarters the sound
Halving the distance, quadruples the sound
PROXIMITY EFFECT:
When using a unidirectional microphone, the closer you get to the element the "bassier" the sound gets.
How A Speaker Works:
A speaker consists of a circular permanent magnet surrounding a freely moving coil, which is attached to a cone shaped diaphragm.
Alternating current, generated by a microphone, a tape-head, amplifier, radio, or other transducer, flows through the coil of the speaker. The current, alternating at the same frequency as the sound waves that generated it, induces an alternating magnetic field in the coil. As the polarity of the magnetic field of the coil alternates, it is alternatively attracted to and repelled by the permanent magnet. This causes the coil to vibrate. The vibrating coil causes the attached cone shaped diaphragm to vibrate & reproduce the sounds generated by the original source.

A condenser microphone is a highly sensitive transducer.
It contains a thin diaphragm suspended very close to a metal disk called a back-plate and separated by an insulating layer called a dielectric. Both the diaphragm and back-plate are electrically charged. One of these is positively charged and the other negatively. This creates a capacitance field between the two plates. The sound is captured when sound waves vibrate the diaphragm. The resulting change in capacitance varies the voltage of the back-plate. This voltage variation is the audio signal. As the diaphragm moves closer to the positive plate of the capacitor, the electrostatic attraction between the plates increases. This causes current flow to the diaphragm. As the diaphragm moves away from the positive plate, the electrostatic attraction between the plates decreases. This causes a flow of current back to the positive plate. The current alternates at the same frequency as the sound waves, is amplified, travels through a mixer, and then finally to a speaker.
A capacitor is an electrical device designed for storing electric charge, generally consisting of two parallel conducting plates separated by an insulating layer called a dielectric. Capacitance is determined by plate area, distance between the plates, and the ability of the dielectric to support electrostatic forces. Larger plates provide greater capacity to store electric charge. So as the area of the plate increases, capacitance increases.

Capacitance is directly proportional to the electrostatic force field between the plates. This field is stronger when the plates are closer together. Therefore, as the distance between the plates decrease, capacitance increases. Dielectric materials are rated based upon their ability to support electrostatic forces in terms of a number called a dielectric constant. The higher the dielectric constant the greater the ability of the dielectric to support electrostatic forces. So, as the dielectric constant increases, capacitance increases.
Faraday's Magnetic Field Induction Experiment
When Michael Faraday made his discovery of electromagnetic induction in 1831, he hypothesized that a changing magnetic field is necessary to induce a current in a nearby circuit. To test his hypothesis he made a coil by wrapping a paper cylinder with wire. He connected the coil to a galvanometer, and then moved a magnet back and forth inside the cylinder. As the magnet moves back and forth, the galvanometer needle moves, which indicates that a current is induced in the coil. The needle immediately returns to zero when the magnet is not moving. Faraday confirmed that a moving magnetic field is necessary in order for electromagnetic induction to occur.

Lightning: An Example of a Natural Capacitor
Clouds and the ground can act in unison to mimic a huge natural capacitor. The process of evaporation and condensation of atmospheric water within clouds causes water droplets to collide with dust, ionizing radiation, and each other. These collisions cause electrons to be knocked off the particles creating a charge separation in the clouds. Negative electrical charges accumulate at the base of clouds. The base of the clouds can be compared to a negative plate of a capacitor. These charges induce positive charges to accumulate in the ground, comparable to the positive plate of a capacitor.
The air between the clouds and ground becomes the dielectric of this natural capacitor. The electrostatic field between the clouds and the ground can produce ions and free electrons in the air. Eventually the difference in potential between the clouds and the ground can become so great that the air dielectric begins to break down. The ions and free electrons provide the necessary path that short-circuits this natural capacitor, initiating a flash of lightning.

Microphone facing top of page in diagram, parallel to page:
Omnidirectional Subcardioid Unidirectional- Cardioid
Supercardioid
Line Gradient-Shotgun
Bi-directional-Figure 8
Unidirectional- Cardioid
Hypercardioid
Stereo
Supercardioid
Bi-directional-Figure 8
Omnidirectional
Mid-Side
Mid-Side

Integrated cross-polar ratio - where fco and fcx are the measured co-polar and cross-polar patterns http://kentrubshaw.blogspot.com/2010/03/recording-in-pro-tools-mixing-inlogic.html
The MS technique is a coincident technique (mics are close together) employs a bidirectional (figure- eight) microphone facing sideways and another unidirectional microphone at an angle of 90°, facing the sound source. The technique is completely mono compatible and used widely in films and audio recording. The signal from the figure-eight mic is duplicated and its phase reversed, the two duplicate signals are panned equally from left to right. The middle component (as its name suggests) is panned to the centre.
The stereo depth becomes very wide and imaging very precise. When one turns the sides all the way down, the track becomes mono. When the sides are panned to the centre, because they are 180 degrees out of phase, they perfectly cancel each other out leaving just a mono signal.
X-Y Pattern