Direct Injection, or Direct Instrument Box. A device which accepts the signal input from a guitar, bass, or keyboard and conditions it to conform to the requirements of a microphone signal at the output. The output is a mic-level, balanced signal with a low source impedance, capable of driving long mic cables. There is usually a facility to break the ground continuity between mic cable and source to avoid unwanted ground loop noises. Both active and passive versions are available, the former requiring power from internal batteries or phantom power via the mic cable. Active DI boxes generally have higher input impedances than passive types and are generally considered to sound better.

the movable membrane in a microphone capsule which responds mechanically to variations in the pressure or pressure gradient of sound waves. The mechanical diaphragm vibrations are converted into an electrical signal usually through electromagnetic or electrostatic techniques such as ribbon, moving coil, capacitor or electret devices.

An abbreviation for ‘Direct Instrument’ or ‘Direct Inject’ - the two terms being used interchangeably. Used when an electrical sound source (eg electric guitar, bass or keyboard) is connected directly into an audio chain, rather than captured with a microphone in front of a amp/loudspeaker.

One or more physical click-stops which can be felt when a rotary control is moved. Typically used to identify the centre of a control such as a pan or EQ cut/boost knob, or to give the impression of preset positions on a gain control.

An alternative term for mixer (See also console).

The time between a sound or control signal being generated and it auditioned or taking effect, measured in seconds. Often referred to as latency in the context of computer audio interfaces.

The process of rearranging the files on a hard disk so that all the files are as contiguous as possible, and that the remaining free space is also contiguous.

A device intended to prevent the transmission of physical vibration over a specific frequency range, such as a rubber or foam block.

A form of ‘spaced microphone’ arrangement in which three microphone capsules (usually, but not always, with omnidirectional polar patterns) are placed in a large triangular array roughly two metres wide, with the central microphone one metre further forward. Sounds approaching from different directions arrive at each capsule at different times and with slightly different levels, and these timing and level differences are used to convey the directional information in the recording. The timing differences between channels can result in unwanted colouration if they are combined to produce a mono mix.

The progressive reduction in amplitude of a sound or electrical signal over time, eg. The reverb decay of a room. In the context of an ADSR envelope shaper, the Decay phase starts as soon as the Attack phase has reached its maximum level.