Audio

AUDIO FACTS AND TIPS
Sound is a pattern of pressure waves that move through the air. The frequency of these waves determines the pitch of the sound--how low or high it sounds. Sound frequency is measured in cycles per second or Hertz (Hz). The range of human hearing is generally considered to be from about 20Hz at the low end and 20 kHz at the high end. But in practice, most adults only hear as high as 12kHz to 19kHz (especially if you've spent lots of time with loud headphones or at loud rock concerts).
Microphones turn small variations in air pressure into electrical signals. Air waves hitting a sensitive diaphragm inside the mic are translated into electrical energy. Selecting the right mic and placing it to pick up a signal optimally are key.
Types of microphones and connectors:
Condenser--the most popular style of microphone used in recording studios (home or commercial). Condenser mics are sensitive and accurate, but they can also be expensive. Recently, however, condenser mics have come down in cost, and you can buy a decent one for around $200. Very good ones start at about $500. Tends to have a well-rounded frequency response. Condenser mics need a small amount of voltage (between 9 and 48 volts) to function. If you use a condenser mic, make sure that it has its own internal battery — or that you have a preamp or mixer equipped with phantom power.
The condenser microphone has an extremely thin metal (or metal-coated plastic or Mylar) diaphragm (the part that senses the signal). The diaphragm is suspended in front of a metal plate (called a backplate). Polarizing voltage is applied to both the diaphragm and the backplate, creating a static charge in the space between them. When the diaphragm picks up a sound, it vibrates into the field between it and the backplate. This produces a small signal that can then be amplified	Sony handheld, stereo, condenser microphone connects to camera with MINI connector	Lavalier condenser microphone w/Professional XLR connector	Lavalier condenser microphone w/Professional XLR connector
Dynamic--most effective when working with relatively loud sound sources that don't contain a lot of very high-frequency detail, tough as old boots, which makes them good for live work, or for any application within six feet of a drummer! Looks like a mesh ball on a stick, relatively inexpensive and hard-wearing, doesn't need a power supply or batteries to make them operate. In live sound, nearly all the mics used are dynamics, they can handle a lot of volume (technically known as SPL, meaning Sound Pressure Level), which makes them perfect for extremely loud signals, such as drums, amplifiers, and some rock vocals. Tends to accent the middle of the frequency spectrum .
A lightweight diaphragm, usually made of plastic film, is attached to a very small coil of wire suspended in the field of a permanent magnet. When a sound causes the diaphragm to vibrate, the whole assembly works as a miniature electricity generator, and a minute electric current is produced. Because the electrical output is so very small, it has to be amplified using a mic preamp before it is large enough to be useful.	Handheld dynamic microphone uses professional XLR connector
Capacitor/Electret	--Capacitor microphones are more expensive than their dynamic counterparts, but they are also much more sensitive, and can capture high-frequency detail much more accurately. These have now been developed to the point where they can rival true capacitor quality for a much lower price. Instead of applying an electrical charge to the microphone capsule via an external power source, electret mics use a diaphragm made from an insulating material that has a permanent electrical charge. A preamplifier is still needed, but this can be built very cheaply, and will run from a battery in some cases.
PZM--Pressure Zone Microphone Special type of condenser microphone. Also known as a boundary microphone, this type of microphone uses a sound phenomena called the boundary effect. PZM mics are quite unusual-looking. They are flat and don't really look like microphones at all. They work best when placed against a hard, flat surface at least one meter square; for example, a tabletop or wall. These mics are often used in conference situations, where they can be placed conveniently and unobtrusively in the middle of the table.
A small condenser microphone is mounted face-down a short distance from the reflective boundary plate. This creates a pressure zone between the plate and the mic. The microphone detects changes in this pressure zone, rather than the conventional method of detecting changes in the surrounding air pressure (i.e. sound waves). Advantages of PZM Microphones The main advantage of this technology is the elimination of interference from reflected sound waves. A normal microphone will pick up sound waves from the primary source and also any reverberations, which can result in unnatural sound reproduction. In the pressure zone microphone, sound waves are always in phase and there is no interference. PZM mics also tend to have a smooth frequency response, good off-axis consistency and strong output levels.
MICROPHONE CONNECTORS	MINI (consumer level)		XLR (Professsional)

Microphone design/types used in this video class	Handheld	Lavalier	Wireless lavalier-includes receiver and mic, transmitter and connector to camera