The addition of harmonics that were not present in the original signal caused by non-linearities in an electronic circuit or audio transducer.

High frequency components of a complex waveform, where the harmonic frequency is an integer multiple of the fundamental.

Shorthand abbreviation for Effects.

The lowest frequency component in a harmonically complex sound. (Also see Harmonic and Partial.)

A 7-microphone array surround-sound, broadly equivalent to the stereo Decca Tree. Conceived by Akira Fukada when he worked for the Japanese state broadcaster NHK. The front Left, Centre and Right outputs are generated from a trio of mics arranged in a very similar way to a Decca Tree, with the left and right outriggers spaced 2m apart, and the centre mic 1m forward. The Rear Left and Rear Right channels come from mics spaced 2m apart placed and 2m behind the front outriggers. Instead of using omni mics like a Decca Tree, all five mics are usually cardioids, aimed 60 degrees outwards to maximise channel separation. These five mics are usually supplemented with an extra pair of omni outriggers placed midway between the front and rear mics.

Frequency Shift Keying. An obsolete method of recording a synchronisation control signal onto tape by representing it as two alternating tones. (Also see timecode)

The variation in amplitude relative to the signal frequency. A measurement of the frequency range that can be handled by a specific piece of electrical equipment or loudspeaker. (Also see Bandwidth)

The number of complete cycles of a repetitive waveform that occur in 1 second. A waveform which repeats once per second has a frequency of 1Hz (Hertz).

The process by which the available space on a disk drive gets split up into small, sometimes unusable, sections due to the storing and erasing of files.

A procedure required to ready a computer disk or digital tape for use. Formatting organises the medium into a series of ‘electronic pigeon holes’ into which data can be stored. Different computers often use different formatting systems.