Microphone Presentation

Microphones What is a microphone?

A microphone is an example of a transducer, a device that changes information from one form to another. Sound information exists as patterns of air pressure; the microphone changes this information into patterns of electric current. Sound waves cause movement of a thin metallic diaphragm and an attached coil of wire. A magnet produces a magnetic field which surrounds the coil, and motion of the coil within this field causes current to flow. Dynamic

Condenser

Dynamic microphones are robust, relatively In a condenser microphone, also known as inexpensive and resistant to moisture. They a capacitor microphone, the diaphragm acts include a windshield that the sound enters as one plate of a capacitor, and the through, reducing popping and excess wind vibrations produce changes in the distance being captured. A single dynamic between the plates. This acts as a membrane will not respond to all audio diaphragm, which vibrates due to the sound frequencies. Some microphones for this waves. Changing the capacitance. A reason utilize multiple membranes for the voltage is required across the capacitor for different parts of the audio spectrum and this to work. This voltage is supplied either then combine the resulting signals. This is by a battery in the microphone or by an unusual design and is usually external phantom power. expensive. However many microphones are designed to pick up certain frequencies Electret microphones use a special type of within the audio spectrum, e.g. different capacitor which has a permanent voltage microphones from bass, treble and high built in during manufacture. These do not end sounds, to get best results. The shape need power, however many include of the microphone defines its directivity. Thepreamp’s which do. inner components are majorly important to the sound captured by a microphone.

Which microphone for which job? Voice:

The most common choice of microphone for vocal recording is the condenser; however on stage, dynamic microphones are used as they are much more robust. Microphones like the AKG C1000S large diaphragm condenser are generally the choice for studio vocals. These types usually give a warmer sound to the voice or instrument it is recording. However they do not pick up as wide a frequency range and at such a high speed as small-diaphragm condensers. Drums:

In many cases a coincident pair of cardioid condensers are used to pick up the stereo image of all of the drums, or in some cases to pick up the toms and cymbals. Sometimes referred to as pencil condensers due to their thin and elongated shape. The bass drum needs a special type of super-cardioid dynamic microphone that can stand up to vibration and high pressure from inside the bass drum itself. This microphone is usually specialized as it has to have a high gain output, without creating unwanted distortion or feedback. Speakers work in the same, but opposite way as dynamic microphones. Usually without good quality or precision though. One use is for bass drums, as demonstrated by the Yamaha "Subkick". The toms and snare also usually use specialized microphones that pick up frequencies in the range of 50~16000 Hz. For this application, dynamics are needed as there is a chance that they could be hit by the drummer’s sticks. And they must be a special shape to fit small adjustable and shock resistant rim clips. Guitars:

When recording an amplified guitar via a microphone, one of the most important things to consider is the volume. In most cases, there is no need to crank up the volume, but if you did some condensers may be damaged by the high pressure air waves. Although, to get best results a condenser would be best to pick up the wide range of frequencies and tones that a guitar produces (especially when using effects.)