(tag) – fundamentals

The Electromagnetic Spectrum is the range of all possible frequencies of electromagnetic radiation. See the excellent diagram reproduced by kind permission of Louis Keiner http://www.keiner.us/. The sections of particular interest to IPS members are usually referred to as the Radio Spectrum (although they are mostly used for television!), and are: Low Frequency (LF) covers frequencies…

Direct Current or DC refers to the unidirectional flow of electrons from high to low potential, as opposed to Alternating Current or AC where the flow regularly reverses in direction at a specific frequency. By convention this flow is considered to be from positive to relatively negative points; note that this direction is not the…

Tonader Power, T Power, T12 or AB Power all refer to a method of powering microphones via their cable. This system uses 180 ohm feed resistors and a 12V supply but does not send the DC power as a common mode signal like Phantom Power. The powering is unbalanced and shares the same path as…

The human ear does not react to changes in sound in a simple, linear way. To double the loudness of a sound, say by turning up the volume control on an audio amplifier, most people find that they need to increase the power produced by the loudspeaker by about ten times. If we were to…

Pressure Zone Microphone is a registered trade mark of Crown International, and describes a method of mounting a microphone close to a flat surface to minimise room acoustics. Other variants are described as Boundary Microphones. See http://www.uneeda-audio.com/pzm/

An Interference Tube is simply a long metal tube with a series of circumferential slots cut into it, fitted onto a directional Microphone. These slots produce interference patterns in sound waves from the sides, resulting in partial cancellation of off-axis sounds and a resultant apparent increase in the gain of sounds from directly in front.

Microphones work by sensing minute changes in air pressure. Pressure A pressure operated microphone is essentially a sensitive barometer and reacts only to changes in pressure irrespective of the direction of the sound source. It comprises a sealed box with air inside and a thin diaphragm that deflects for small pressure changes. Some form of…

Contents 1 Sex 2 XLR 2.1 3 pin 2.2 4 pin 2.3 5 pin 2.4 6 pin 2.5 7 pin 3 Jack 3.1 ‘A’ gauge 3.2 ‘B’ gauge 3.3 MIL-plug 3.4 Bantam 3.5 3.5mm 3.6 2.5mm 4 Hirose 4.1 4 pin 4.2 10 pin 5 Tajimi 5.1 12 pin 6 DIN 6.1 2 pin 6.2…

Alternating Current or AC refers to a flow of electrons that reverses in direction in a cyclical manner

Analogue audio signal levels have historically been categorised for professional usage in two groups – microphone level (low) and line level (high). Domestic equipment generally falls into a third category, just below professional line level. Signal levels are measured using units based on the Decibel. There are many different types of Level Meter used for…