Search

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.

Shorthand abbreviation for Effects.

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

The available ‘safety margin’ in audio equipment required to accommodate unexpected loud audio transient signals. It is defined as the region between the nominal operating level (0VU) and the clipping point. Typically, a high quality analogue audio mixer or processor will have a nominal operating level of +4dBu and a clipping point of +24dBu - providing 20dB of headroom. Analogue meters, by convention, don’t show the headroom margin at all; but in contrast, digital systems normally do - hence the need to try to restrict signal levels to average around -20dBFS when tracking and mixing with digital systems to maintain a sensible headroom margin. Fully post-produced signals no longer require headroom as the peak signal level is known and controlled. For this reason it has become normal to create CDs with zero headroom.

A misnomer, but used to refer to digital formats with long word-lengths and high sample rates, eg. 24/96 or 24/192. Audio resolution is infinite and identical to analogue systems in properly configured digital systems. Word-length defines only the system’s signal-to-noise ratio (equivalent to tape width in analogue systems) , while sample rate defines only the audio bandwidth (equivalent to tape speed in analogue systems).

Normally used in the context of the USB computer data interface. A hub is a device used to expand a single USB port into several, enabling the connection of multiple devices. Particularly useful where multiple software program authorisation dongles must be connected to the computer.

A condition whereby the state of a system is dependent on previous events or, in other words, the system's output can lag behind the input. Most commonly found in audio in the behaviour of ferro-magnetic materials such as in transformers and analogue tape heads, or in electronic circuits such a 'switch de-bouncing'. Another example is the way a drop-down box on a computer menu remains visible for a short while after the mouse is moved.

An abbreviation of Integrated Circuit, a collection of miniaturised transistors and other components on a single silicon wafer, designed to perform a specific function.

A reactive component that presents an increasing impedance with frequency. (Also see Capacitor.)