A

a to d analogue to digital conversion or converter (audio)

 

active circuit or device that requires external power (eg battery or phantom power) to function - powered counterpart of passive device (eg passive and active DI boxes)

 

ADAT 4 - 8 channel digital audio optical transmission protocol - Alesis Digital Audio Tape format, a VSH tape based 8 track multi-track recording format developed in the 1980s

 

additive synthesis digital synthesis method that seeks to emulate the way that complex timbres are created in nature by combining multiple sine waves (vibrations) at various amplitudes and frequencies to create a complex wave

 

ADSR attack (time), decay (time), sustain (level) and release (time) - the parameters of an envelope generator - also see envelope generator

 

ADT artificial (automatic) double tracking - the practice of using a delayed copy of a signal to simulate 2 performances

 

AES Audio Engineering Society - oversees the ratification of new agreed standards for audio

 

AES3 2 channel digital audio transmission protocol - balanced professional version of SPDIF

 

AES10 multi-channel channel digital audio transmission protocol - MADI

 

AIFF Audio Interchange File Format - uncompressed PCM audio file format - capable of encoding between 1 and 8 channels in a single data stream - originated by Apple

 

air frequencies between 3.5 and 20kHz in the audio spectrum

 

air pressure a measure of the density of air molecules

 

aliasing (noise) unwanted distortion (side effect) of insufficient sample rate (Nyquist) - creation of low frequency harmonics in a digital audio file during d to a conversion, which were not present at input

 

ambience the mix of direct and reflected sound - the audible character of a space determined by its dimensions and surfaces - short reverb, typically a small room/space

 

amplitude the 'amount' of compression and rarefaction of the air - the voltage of an electrical pressure soundwave - the volume or loudness which the ear perceives

 

analogue (audio) signal that is analogous ('looks like') to the sound it represents - eg an electrical audio signal (voltage) that has the same pattern of changing energy (amplitude) as the air pressure soundwave it represents

 

anti-aliasing filter part of the input stage of an analogue to digital converter - removes any harmonics from an audio signal which are above the highest frequency that the sample rate can accommodate - eg at a sampling rate of 44.1kHz, all harmonics above 20kHz must be filtered out

 

attack (time) synthesis term - the time taken for a soundwave to reach its maximum amplitude at note on

 

attenuate to turn down

 

audio interface a device which allows audio to be sent between a computer (DAW) and external devices (both analogue and digital) - may contain a to d and d to a converters

 

audio spectrum frequency range (bandwidth) of human hearing - 20Hz to 20kHz

 

audio units Apple's proprietary audio plug-in extension standard

 

auxiliary a mixer signal path (bus) accessible from all channels and primarily used to send signals to an effect processor or to setup sub-mixes for fold-back

 

 

B

balanced a wiring/circuit arrangement that requires three cable cores and which involves using common mode rejection to eliminate RF interference and signal loss

 

bandwidth a range of frequencies - eg a microphone capable of 'hearing' frequencies between 40Hz and 18kHz

 

band-pass filter-filter type which passes and boosts or cuts frequencies between two limits - also see notch filter

 

bantam miniature size jack plug favoured by console manufactures for built in patch-bays due to its small footprint

 

bass between 20 and 200Hz in the audio spectrum

 

bi-polar amplitude scale used in waveform diagrams which shows compression (increasing pressure and increasing amplitude), and rarefaction (decreasing pressure and increasing amplitude)

 

bit depth also see word length

 

bit rate measurement of bits in a digital audio data stream - expressed in bits per second (bps) - bit rate effects audio quality - qualitative property of MP3 audio files

 

bleed unwanted sound from an adjacent location or device infecting an audio signal - eg sound from one instrument being picked up by a microphone placed on another instrument

 

BNC digital audio connector used for word clock and MADA (AES10) - a single core and shield coaxial cable used for digital signal transmission

 

bpm beats per minute - measure of tempo

 

BS1770 loudness metering standard - also see loudness

 

buffer an area of memory in which digital audio data is queued/held by an operating system, whilst it waits for CPU processor clock cycles to become available to process it

 

 

C

cabinet a loudspeaker enclosure for an electric guitar or electric bass guitar

 

cable the part of the lead which carries the signal(s) between connectors and devices

 

canon see xlr

 

cardioid a microphone polar pattern which only picks up sound from in front of the diaphragm

 

capacitor microphone see condenser microphone

 

channel voice message (MIDI) primarily performance related message originated from and transmitted by a MIDI controller (eg keyboard) - includes these message types: Note On, Note Off, Polyphonic key pressure, After-touch, Program change, Control change, Pitch bend change

 

chorus (effect)a time domain effect which seeks to simulate the effect of multiple performances/recordings with delay times between 13 and 30 ms and narrow width and medium delay time modulation settings - also see flanging

 

choke (MIDI) a consequence of the serial nature of MIDI whereby multiple channels transmitted over a single connection create timing errors in a the playback of a musical performance

 

closed back headphone design in which sound does not escape from the rear of the ear pieces - suitable for close mic recording

 

common mode rejection balanced audio lead 'arrangement' which eliminates RF interference and maintains signal strength

 

coaxial a cable consisting of a single insulated core/wire and surrounding (braided) earth shield and outer insulation.

 

combo enclosure housing a guitar amplifier and loudspeaker

 

compression increase in air pressure above normal atmospheric pressure - also see soundwave - process for reducing the dynamic range of a signal - also see compressor (audio)

 

compressor (audio) device for altering the dynamic range, at 'macro' and 'micro level', of audio signals - also used to add 'colour' (distortion)

 

condenser microphone microphone design - powered 'studio' microphone with wide frequency response and high sensitivity favoured for vocal recording - also known as capacitor microphone

 

core an inner wire within a cable, normally isolated from other cores by a non conducting insulation sleeve - eg earth, live, and return are each cores

 

crosstalk a situation in which adjacent electrical circuits or devices pickup signals from each other - eg adjacent channels in a mixing desk or adjacent track heads in a multi-track tape recorder head block

 

CV control voltage - pre MIDI signal used to send timing and note information between devices - eg a sequencer and synthesiser

 

cycle a single vibration of a sound source (expansion and contraction)

 

cycles per second (cps) frequency of a sound wave - the number of vibrations (expansion and contraction) per second - measured in Hertz (Hz) - 1 cps = 1 Hz

 

 

D

DAC digital to analogue converter

 

data byte (MIDI) a byte in a MIDI message which carries a value - eg 01111111 (127 maximum volume)

 

DAW digital audio workstation - combination of eg a computer (Mac or PC), i/o hardware, software such as Pro Tools or Logic Pro, plug-ins and virtual instruments

 

diaphragm the part of a microphone that converts air pressure soundwaves into (mic level) electrical pressure soundwaves

 

decay (time) the time it takes for a soundwave (at 1kHz) to decrease in amplitude by 60dB (effectively to silence) - in synthesis, the time taken for the soundwave to reach the sustain level following the attack

 

de-esser frequency conscious compression technology designed to attenuate sibilance

 

diffusion The pattern or spread of reverberation echos - a high diffusion setting will produce a smooth and even sound - a low diffusion setting will result in a lumpy of semi-echoy sound

 

DI (box) direct injection - a device or process primarily used for converting unbalanced to balanced signals and matching the differing impedances of 2 devices - eg connecting the output of electric guitars and electric bass guitars (pickup) directly to a recording system (mic pre-amp)

 

distortion (audio) a condition in which the capacity (dynamic range) of a device or circuit is exceeded such that it is no longer able to accurately represent the input signal - a change in the wave-shape

 

dither low level noise added to an audio signal during conversion to a lower bit rate in order to randomise quantisation errors and improve audio quality

 

drift a digital audio transmission/synchronisation condition in which the overall clocking of samples in one signal, relative to other signals in an integrated system, become delayed

 

driver transducer in a loudspeaker cabinet which converts an electrical pressure soundwave into an air pressure soundwave - a piece of software which translates between an operating system and connected third party devices/hardware (such as an audio interface)

 

DSP digital signal processor - a CPU designed to process digital audio - eg DSPs can be found in hardware effect processors

 

d to a digital to analogue conversion (audio)

 

D-sub 25 (AES59) a multi-pin connector favoured for 8 channel balanced analogue and digital audio interconnection

 

dynamic microphone a microphone without active electronics and which therefore does not require phantom power - generally used to record louder sound sources such as drums and electric guitar cabinets/combos

 

dynamic range the difference between the loudest and quietest parts of a soundwave, or the range of volumes - in an audio device, the ratio between the noise floor (beneath which a sound cannot be heard) and distortion (the point at which the electronics are unable to represent the volume of the soundwave

 

 

E

early reflection the transient of an echo or reverberation - the first echoes (delays) to reach the listeners ear and which play the biggest part in shaping the character of a reverb

 

earth core or pole in audio lead - employed to protect live and return cores in a balanced lead from RF interference - doubles as return in an unbalanced lead - known also as shield, sleeve, screen, external

 

earth lift a switch which disconnects the earth core of a lead in order to eliminate hum, usually found on DI boxes

 

envelope generator (EG) device for controlling amplitude over time (when controlling an amplifier), pitch over time (when controlling an oscillator), filter cutoff point over time (when controlling a filter) - may output a control voltage (CV) or digital signal - also see ADSR

 

expander a processor designed to increase the dynamic range of a signal by reducing the amplitude of low level signals and increasing the amplitude of hi level signals

 

external term for earth in xlr (canon) connector - see also earth

 

 

F

far field area in a space where the indirect reflected sound dominates - area in which reflected sound is greater in amplitude than direct sound

 

filter (eq) a device for isolating and amplifying or attenuating harmonics in a soundwave

 

filter cutoff point (eq) the frequency above, below, or around which amplification or attenuation will take place in a filter

 

filter slope rate of change of amplification or attenuation - also see poles

 

figure of eight a microphone polar pattern which picks up sound from in front of and behind the diaphragm(at o and 180 degrees) but which largely rejects sound from the sides

 

flanging a time domain effect similar to phasing but with longer delay times between 3 and 13 ms and with wider and faster delay time modulation settings - also see phasing

 

flat a sound which has not been eq'd - an audio system, or setup, which passes a signal without affecting it

 

flat frequency response a property of an audio device whereby a signal passing through it maintains its frequency response

 

fold-back headphone monitoring system usually comprising a talk-back mic, monitor signal, headphone amplifier, and headphones

 

frequency rate of vibration of a source (audio) - rate at which a sound cycles (between compression and rarefaction) - expressed in cps (cycles per second) or Hz (1 cps = 1Hz) - determines pitch

 

frequency modulation (FM) Yamaha developed synthesis method which utilises 4 - 6 sine waves in different configurations (algorithms) to modulate each other to create a complex timbre - the first commercially successful (1983) digital synthesis technology - FM was invented by Dr John Chowning (Stanford University)

 

fundamental harmonic - usually the lowest frequency vibration in a complex wave - almost always determines pitch in a repetitive sound

 

 

G

gain control which determines the amount of amplification of a signal

 

gate pre MIDI (CV) system for controlling the sounding of notes on (primarily) analogue synthesisers - also used to trigger envelope generators

 

graphic equaliser device with multiple fixed frequency band-pass filters each covering a narrow part of the audio spectrum

 

ground loop unwanted low frequency signal in a signal path between devices - usually occurs when there are multiple paths to earth in a connection

 

guitar level (signal) weak high impedance audio signal produced by guitar pickups - unbalanced

 

 

H

harmonic(s) individual sinusoidal vibration within a complex wave

 

head electric guitar or electric bass guitar amplifier

 

headphone(s) monitoring device worn on head!

 

head-room dynamic range safety margin in an audio system - range of increasing amplitude above maximum at which distortion will not occur

 

hertz (Hz) measurement unit for sound wave frequency - number of cycles (or vibrations) of a source per second - see also cycles per second

 

hi-frequency decay/damping control which lets you set a shorter reverb time for the high frequencies - useful when emulating high frequency absorption

 

hi-pass (filter) a filter which attenuates lower harmonics

 

hiss audible noise caused by random motion of electrons in an electrical circuit

 

hyper-cardioid microphone polar pattern which only picks up sound from in front of the diaphragm but from a more focused area than a cardioid pattern - also see cardioid

 

Hz hertz - term used to express cycles per second (frequency) of a soundwave - 1 Hz = 1 cps

 

 

I

impedance (z) an opposing force in an electrical (AC) circuit, which presents 'resistance' to a signal (voltage) - in a DC circuit the terms impedance and resistance can be used interchangeably

 

impedance matching the process of matching 2 or more device in a chain (eg microphone and mic pre amp) so that resistance does not adversely effect the devices operation - also see DI (boxes)

 

insert lead a lead which facilitates the inserting of an unbalanced processor into a signal path (typically a cost effective mixer) in which a TRS jack plug and socket is employed for both send and return signal paths

 

i/o a means to transfer audio signals in and out of a DAW, typically by way of some kind of audio interface

 

 

J

jack (plug) connector commonly used for electronic instrument, headphone and guitar interconnection, among others - 1/4" and mini versions - 2 pole (mono) and 3 pole (stereo) versions

 

jitter timing errors in the sample rate of a digital audio data stream

 

 

K

key input side chain input connection which allows an external signal to control a process - eg a hat hat controlling the opening and closing of a noise gate

 

kHz audio frequency unit - measurement of cycles of a waveform expressed in thousands of cycles per second - 1000 cps = 1kHz

 

knee (compression) hard or soft knee - determines the rate of change towards the compression ratio as amplitude approaches the threshold level - eg hard knee will impose the full ratio as soon as the signal exceeds the threshold

 

 

L

latency the time delay between a digital audio signal entering a process or device and returning from it

 

light-pipe Alesis name for their ADAT fibre optic digital audio transmission protocol - also see ADAT

 

limiter (audio) device for altering the dynamic range of audio signals - limiting is compression at a high ratio setting (at or close to infinity), in which peaks in amplitude are not permitted to exceed the threshold level - also used to add 'colour' (distortion) - also see compressor

 

line level strong audio signal suitable for recording, processing and mixing - created by mic pre-amps and electronic instruments etc, used by mixers, tape recorders, outboard processors, DAWs etc

 

LFO low frequency oscillator - in synthesis, used to modulate audio signals (pitch, amplitude) or a filters cutoff point

 

lo-pass (filter) a filter which attenuates higher harmonics

 

loudness perceived loudness - how we experience level and volume - perceived loudness changes according to environment (home, car, cinema) and individual physiology. Average loudness standards have been established (BS1770) to permit the development of standard metrics and algorithms for metering

 

loudness unit loudness measurement metric

 

LUFS loudness units full scale - the agreed BS1770 loudness measurement unit

 

loudness range the variation in loudness - loudness range can be greater for home and the cinema where background noise is low (typically 20 LU is used) than for in car or in flight (where a range of 8 LU is appropriate

 

 

M

MADI see AES10

 

microphone a device (transducer) which converts air pressure soundwaves into (mic level) electrical pressure soundwaves

 

mic level (signal) weak audio signal produced by microphones

 

mic pre (-amp) an amplifier designed to convert mic level signals to line level

 

MIDI musical instrument digital interface - a protocol largely used to record MIDI events generated by performance on MIDI controllers (eg keyboards) - the MIDI specification consists of 2 parts: the MIDI language, in the form of a set of messages or commands, and the details for the electrical way those messages are transmitted and received, including the hardware MIDI interface and cables

 

MIDI in MIDI interface port which receives MIDI messages from the MIDI out port of a transmitting device

 

MIDI out MIDI interface port which send MIDI messages to the MIDI in port of a receiving device

 

mid range frequencies between 200Hz and 2kHz in the audio spectrum

 

MIDI sync (clock) an obsolete synchronisation protocol which contains 'dumb' frame information - a system to be synchronised must be started from the beginning each time it is run - superseded by MTC

 

MTC (MIDI time code) MIDI version of SMPTE containing a timing clock with individually identifiable frames - eg EBU 25 fps (frames per second)

 

MIDI thru MIDI interface port which sends a duplicate of a signal received at an adjacent MIDI in port

 

mp3audio codec originally developed to overcome the storage and bandwidth demands of red book quality audio (ie 44.1kHz / 16-bit)

 

multi-timbral (MIDI)a MIDI device (eg sound module) capable of playing multiple MIDI sequences/parts on multiple MIDI channels simultaneously

 

 

N

near field a monitoring position in which the direct sound (from the loudspeakers) dominates - area in which direct sound is greater in amplitude than reflected sound

 

noise gate an audio processor for attenuating audio that falls below a chosen level - frequency conscious gating determines the gate action by frequency content - side chain gating controls the gate action with a control signal or MIDI message

 

normalisation a wiring system that connects vertically adjacent sockets of a patchbay when patch cord leads are not inserted - or - an algorithmic process which changes the highest valued byte (sample) in a digital audio file to the digital maximum (eg 111111111111111111111111) and changes the value of all other bytes relative to it

 

notch filter a band pass filter designed to cut frequencies

 

Nyquist theory digital audio theory that states that the sample rate should be a little over twice the amount of the highest audio frequency (harmonic) to be recorded if poor sound quality is to be avoided

 

 

O

omni-directional a microphone polar pattern which picks up sound from 360 degrees

 

open back (headphones) design in which sound emits from the rear of the ear pieces

 

oscillator electronic sound source - creates an electrical pressure soundwave or digital equivalent

 

overload to exceed the dynamic range, or capacity of a device or electronic circuit - also see distortion

 

 

P

pan to place a sound within the stereo field - to narrow or widen the stereo image of a stereo signal

 

parametric (eq) an equaliser circuit with frequency select, cut and boost, and bandwidth (Q) controls

 

passive circuit that does not require external power to function - a loudspeaker without a built-in amplifier

 

patchbay row(s) of sockets enabling easy and flexible interconnection of devices wired to rear terminals - eg audio (bantam, 'B' type etc), digital, MIDI etc

 

PCM Pulse Code Modulation - digital data stream which uses pulse (square) waves to represent audio - commonly refers to uncompressed files (AIFF, WAV, etc)

 

phantom power balanced audio line system for powering microphones and DI boxes via audio leads - eg typical voltage sent from a mic pre-amp to a capacitor microphone is 48v

 

phase relationship between two or more identical signals or identical harmonics within two or more dissimilar signals

 

phasing audio effect which creates a dynamic comb filtering effect by slowly modulating a 1-3 ms (typically) time difference between identical signals or identical harmonics within two or more dissimilar signals - invention/discovery as an effect attributed to Geoff Emerick

 

phase distortion synthesis form of synthesis, which uses an algorithm to create a sine wave, and then uses a second algorithm to distort the "shape" of the sine wave to create a totally new waveform - developed by Casio in the 1980s

 

phono a record player, or record player level signal (cartridge) which requires 'de-coding' by a phono pre-amp prior to amplification - a cost effective unbalanced audio connector widely used for hi-fi connections and SPDIF coaxial leads

 

physical modeling synthesis a form of digital synthesis which utilises fast, powerful digital signal processors (DSPs) and high quality digital to analogue converters (D.A.Cs) - the synthesiser will take the form of either a program, which may run on a computer (normally called a soft synth or plug-in ), or a dedicated hardware device in the form of a rack module, or keyboard synth

 

pin-out the configuration of poles in a multi-pole connector such as a D-sub 25 (AES59) - eg the Yamaha and Tascam D-sub 25 pin-outs for digital 8 channel audio interconnection differ

 

plate analogue reverb device that simulates reverb with transducer attached to a suspended sheet of metal which is vibrated

 

polar pattern the pattern, or area, of sensitivity around a microphones transducer - also see, cardioid, figuer-of-eight, omni-directional

 

polarity property of a single audio signal - the 'direction' of travel from positive to positive or positive to negative (reverse) - a wiring arrangement for audio leads

 

pole strength of the slope at the filter cutoff point - eg 1-pole = 6dB/octave, 3-pole = 18dB/octave - contact or wire in a wiring arrangement (eg earth, live and return are all poles)

 

power soak a device used by guitarists to attenuate the signal sent from an amplifier to a loudspeaker/cabinet

 

pre-delay In a large room there will be a delay between the direct sound and the ER’s

 

presence accentuation of upper mid range frequencies approx between 2 and 6kHz

 

proximity effect tendency of microphones to accentuate low frequency harmonics when a sound source is very close to the microphone (typically within 2-3 inches)

 

pulse wave oscillator created square wave with its wavelength modulated (pulse width modulation) to create a range of unique timbres - useful sound source for piano and flute type sounds

 

pumping generally undesirable effect of fast volume changes resulting from inappropriate setting of attack and release on a compressor or limiter

 

punch frequencies between 70 and 180Hz in the audio spectrum

 

 

Q

q (bandwidth)band-pass or notch filter control which determines how many frequencies around the centre frequency are to be affected - the ‘shape’ or ‘bell’ like pattern of attenuation

 

quantisation (errors) the rounding up or down of sample measurements during analogue to digital conversion - a condition of all digital systems produced by the finite nature of values (word length) in a sample (byte) - can be reduced by increasing word length

 

 

R

rarefaction decreasing air pressure (below normal atmospheric pressure) - also see soundwave

 

ratio (compression) the ratio of attenuation of an audio signal that exceeds the threshold level - eg 3:1 (a signal which exceeds the threshold level by 3dB will be turned down by 2dB, and only 1dB of signal level above the threshold level will output)

 

re-amp(ing) the process of sending a pre-recorded performance (eg guitar) back out of a recording system to be processed through an amplifier (eg guitar) and re-recorded to a new track

 

red book the CD file format standard for audio CDs

 

release synthesis term - the time taken for a soundwave to decay to silence at note off

 

return (interconnection) mirror image (180 degrees out of phase) copy of live signal in a balanced lead

 

return (mixer) an input channel that returns the output of an effect processor to the mix bus

 

RF interference air born interference (Radio Frequency) which primarily adversely effects audio signals during transmission (leads)

 

reverb time (RT60) The length of time it takes for the level of reverberation at 1kHz to decrease by 60dB (virtually to silence). This depends on several factors, room size, shape, type of reflective surfaces etc.

 

ribbon microphone a type of microphone that utilises a thin metal ribbon as a transducer - characterised by a smooth hi-end response and bi-directional pickup polar pattern

 

running status a MIDI system condition in which the transmission of duplicate status bytes is suspended until the message changes

 

 

S

sample a single measurement of amplitude represented by a byte in a digital audio data stream/file - a finite digital recording usually of several bars of a recording or a single note played by an instrument

 

sample frequency see sample rate

 

sample rate the number of measurements of amplitude per second which a digital audio file contains, - eg 44,100 per second, also expressed as sample frequency (44.1kHz)

 

s & s synthesis (sample & synthesis) a synthesis methodology developed by Roland in the 1980s in which the transient portion of a patch/sound is represented by a short PCM sample, as is the sustain portion (which is looped), with the complete sound being processed by a conventional subtractive filter, amplifier, LFO and ADSR modifier architecture

 

sawtooth wave oscillator created waveform - useful for creating brass and string (bowed) instrument type sounds

 

screen see earth

 

shelving filter applies cut or boost to frequencies above or below a specific point (filter cutoff) - a shelving filter can be said to cut or roll-off the unwanted portions of a sound

 

shield see earth

 

sine wave the purest and simplest soundwave vibration, unfound in isolation in nature, can only be created in its pure form by an oscillator - sinusoidal motion - a perfect, regular and consistent vibration of expansion and contraction of a source

 

side chain a routing process whereby a copy is taken of a signal to be processed and then used to affect that signal in some way eg to determine compression or noise gate action

 

slew rate the speed with which an amplifier can respond to sudden increases in amplitude (transients)

 

sleeve see earth

 

SMPTE - synchronisation timecode developed by the Society 0f Motion Picture and Television Enginners union to facilitate the editing of film, audio and foley - a system for synchonising multiple audio recording devices such as tape recorders and computers

 

soundwave sound itself (audio) - the characteristic pattern or timbre of a sound

 

source that which is creating a soundwave

 

SPDIF Sony Phillips Digital Interface - stereo coaxial and fibre optic digital audio transmission protocol used for consumer and cost effective interconnection of devices

 

speakon Neumann developed latching/locking interconnect for power amplifier loudspeaker connections

 

spill see bleed

 

square wave comprise only of odd integer multiples of the fundamental harmonic (x 1, 3, 5, 7 etc) - created by oscillators, requiring at least 20-30 harmonics to produce a good square wave - useful sound source for harp, xylophone ad percussive type sounds

 

status byte (MIDI) the first byte in a MIDI message, and the one which determines the type of message and MIDI channel - eg note on channel 4

 

stems sub mixes with a mix - eg a stem may group all the drum tracks together so that their overall level can easily be balanced with the other instruments/tracks in a mix

 

sustain (level) synthesis term - the level at which the soundwave stays following decay and whilst a note is held

 

system common message (MIDI) sub-set of MIDI system messages such as Song Select, MIDI Time Code, and Song Position Pointer

system real-time messages (MIDI) time critical priority message that may occur at any time, even in the middle of another MIDI message - includes MIDI Clock, Song Start/Stop, and Active Sensing

 

systems exclusive sub-set of MIDI system messages primarily used to transfer device set-up data such as a Patch or Bank Dump used to describe the settings of a particular sound in a synth or a program in an FX processor

 

 

T

talk-back circuit involving a microphone and amplifier (usually headphone) which allow the recording engineer to speak to performers in an adjacent recording room (area)

 

target loudness the LUFS measurement target value - typically -23 LUFS

 

threshold level above or below which audio signals will be affected in an audio process(or) - eg compressor threshold control which sets the level above which compression will take place

 

time domain effect effect that uses the principals of tape delay (delayed copies of signals) to produce echo, phasing, flanging, chorus, ADT and conventional delay effect

 

timbre the character of a sound - a signature combination of harmonics

 

Toslink widely used fibre optic lead standard used for SPDIF, ADAT and AES digital audio interconnection - developed by Toshiba for the exchange of 'RAW' PCM data streams between their hi-fi devices

 

transducer a device which converts one form of energy to another - eg a microphone diaphragm which converts air pressure soundwaves into (mic level) electrical pressure soundwaves

 

transient the attack, or beginning, of a soundwave - to a large extent determines the character (timbre) of a sound

 

treble frequencies between 3 and 20kHz in the audio spectrum

 

TRS tip, ring, sleeve - the 3 poles (contact points) of a 1/4" 'stereo' jack plug

 

 

U

unbalanced wiring/circuit arrangement that requires two cable cores - suitable for line level signals transmitted over short distances (less than 10 meters)

 

uni-directional a microphone polar pattern in which sound is only picked up from one direction

 

unity gain the level at which the amplitude of a signal exiting a system is identical to that at which it entered - ie the device/circuit applies no attenuation or amplification

 

 

V

vari-speed a control for changing the speed of a tape recorder - parameter of time domain effects such as phasing and flanging

 

vector synthesis method developed by Dave Smith at Sequential Circuits whereby a joystick controls the proportional mix amounts of 4 properties, typically waveform, envelope and filter cutoff

 

vibration see harmonics

 

vibrato a pitch modulation effect usually achieved electronically by modulating the pitch of an oscillator with an LFO or by bending the strings of a guitar with a vibrato (whammy) bar

 

 

W

warmth frequencies between 175 and 350Hz in the audio spectrum

 

waveform (diagram) pictorial representation of a soundwave showing amplitude change over time - the character, or timbre, of a sound

 

wavelength the physical distance between two adjacent points on a sound wave (from any point on one cycle to the same point on the following cycle) - denoted by the Greek letter lambda - determined by frequency - low frequency sounds have a longer wavelength than hi frequency sounds

 

wavetable synthesis form of digital synthesis that involves sequentially cycling through (wave sequencing) or morphing between (vector synthesis) a number of waveforms over time - developed by Sequential Circuits in 1986 (Prophet VS)

 

word clock digital audio timing signal running at the sample rate of the system

 

word length the number of bits in a binary byte - eg a digital word represents a single sample (measurement of amplitude) in a digital audio data stream or file - word length determines the dynamic range of the audio file

 

 

X

xlr professional connector with 3 terminals suitable for balanced leads - x=external, l=live, r=return - also known as canon

 

 

Y

y-lead lead used to copy/split an audio signal - also see insert lead

 

 

Z

z see impedance