Glossary of Terms

Understanding many of the hundreds of terms used in a recording studio by producers, engineers, composers, and musicians can be an overwhelming task. We hope to help eliminate the confusion by compiling an on-line glossary that will attempt to define commonly used buzzwords and jargon, both subjective ("I need a warm, weighty, yet puffy bass sound here...") and straight-forward ("Did you join ASCAP yet..."). Using the glossary will not make you an expert overnight, but it will help keep you in the know and keep you abreast of all the specialized terminology that seems to grow incessantly.

You can use the glossary as a reference source simply to look up a term or you can browse the definitions in an attempt to become familiar with a wide variety of new terms. Whichever method you choose, we hope you find this glossary to be a valuable tool in learning the talk of the musical and studio trades.


A listening comparison between two distinct audio sources, whose levels have been matched. The comparison is done by rapidly switching from one to another. You can use this technique to reference your mix against that of a commercial CD.

Accent microphone

Also referred to as 'spot microphone', a closely-placed mic that is ultimately mixed with a distantly-placed mic to improve the tonal balance, as a special effect, or to add presence.

Access jacks

Two separate jacks or one tip-ring-sleeve jack on a mixing board that allow the signal to be routed from the input channel, to an effects device or signal processor, and back into the input channel. Inserting a plug into the access jacks breaks the signal flow, and allows the inclusion of a compressor, exciter or other device.

AD/DA converters

AD converters convert analog audio signals to digital; DA converters convert digital audio back to analog.


An acronym for attack, decay, sustain, and release, the four stages of a standard envelope generator.


An acronym for the Audio Engineering Society.


Professional digital audio standard developed jointly by the Audio Engineering Society (AES) and the European Broadcast Union (EBU). The standard describes a format for transmitting stereo digital audio through a stereo cable (such as fiber optic, coaxial, or balanced XLR).


A MIDI message that reports the amount of pressure applied to the keys after they have been pressed.


A mix where the instruments sound as though they are surrounded by a large reflective space full of air, with good high-frequency reflections. Also refers to tracks where true stereo imaging has been captured, as opposed to panned mono tracks.


A method or script for creating an outcome. For synthesizers, an algorithm generally refers to the parameter values that create a specific sound.


The fine-tuning of tape-head azimuth and tape-recorder circuitry to achieve optimum performance from the type of tape being used.

Alignment tape

A pre-recorded tape containing various tones for alignment of a tape recorder.


The acoustics, reverberation and early-reflections in a room. Also the audible sense of a room surrounding a recorded instrument.

Ambiance microphone

A mic placed at a distance from the sound source in order to pickup room ambience.


A device that increases the amplitude of the voltage, power, or current of a source signal, making an audio signal louder.


An audio signal is an electrical representation of, i.e., is analogous to, a sound waveform. The signal's voltage fluctuates in the same pattern as the speaker cone that reproduces it. Analog synths use oscillators, filters, amplifiers and other electrical components to create electrical signals analogous to the audio wave forms they are trying to represent.

Analog-to-Digital Converter

Also known as 'A/D converter', an electrical circuit or chip that converts an analog audio signal into a digital bit stream.


To play the notes of a chord one after another instead of at the same time.


An acronym for the American Society of Composers, Authors, and Publishers. ASCAP is one of several performing rights organizations which protect artists' and publishers' performing rights. ASCAP collects, handles and distributes royalties for member composers and publishers whose music has been played or performed publicly.


An acronym for American Standard Code for Information Interchange. A standard code for representing text (characters, numbers, special characters, etc.) inside a computer. ASCII is also one of the codes used in the transfer of data or files between computers.


Also known as 'channel assign', to send or route an audio signal to one or more selected mixer channels.


The absence of all tonality in music; the term originally came about to describe the music of Schoenberg.


The beginning of a note. The first portion of a note's envelope in which a note rises from relative silence to its maximum volume.

Attack time

When using a compressor, the time it takes for gain reduction to occur in response to a musical attack.


To reduce the level of a signal.


In a mixing console, an adjustable resistive network that reduces the microphone signal level to prevent overloading of the input transformer and mic preamplifier.

Automated mixing

Using a computer or computer-enhanced mixer to remember mixer settings, mute switchings and fader movements, so that a mix can be duplicated, edited or refined in multiple stages.

Auto punch

The process of automating punch in and punch out on a digital recorder, sequencer or tape recorder. Typically, the exact times (down to the hundredth of a second) of punch in and out may be entered, allowing precise overdubbing.

Auxiliary bus

Also known as 'Effects bus' or 'Aux bus', the bus that feeds signal processors, monitor mixes, or effects devices.

Auxiliary send

Also known as 'Effects send' or 'Aux send', the control on a mixer that determines the level of channel signal sent to a signal processor, such as a reverb or chorus unit.


A type of measurement made through a filter with a specific frequency response. An A-weighted measurement is taken through a filter that simulates the frequency response of the human ear.


In a tape deck, the angular relationship between the head gap and the tape path.

Azimuth alignment

The adjustment of the playback or record head to achieve proper alignment (90 degrees) with the tape path.


A recording technique of cueing up a musical background to a voice track so that the music ends simultaneously with the voice-over.


The relative volume levels of various instruments or tracks.

Balanced line

A cable (such as a three-pin XLR mic cable) with two conductors surrounded by a shield in which each conductor is at equal impedance to the ground. With respect to ground, the conductors are at equal potential but opposite polarity. The balanced line reduces noise because as the two conductors pick up noise, the opposing polarity ensures the noise is canceled when the inverted signal on one conductor is 'added' to the original signal on the second conductor after the signal reaches the destination.


A track or mix with emphasized low frequencies, at about 200-250 kHz. Also, an acoustic or electric guitar with a good low-midrange frequency response.

Bandpass filter

In a crossover network, a filter that passes a band or range of frequencies but sharply attenuates or rejects frequencies outside the band.

Basic tracks

Recorded tracks of rhythm instruments (bass, rhythm guitar, drums, keyboards).

Bass trap

An assembly whose function is to absorb low-frequency sound waves.


A track or mix with emphasized low frequencies, at about 200-250 kHz.

Baud rate

The symbol frequency being used to transmit data over a communications line or a MIDI cable. Baud rate is often used interchangeably with bps (bits per second), although incorrectly. For example, both CCITT V.22bis (2400 bps) and CCITT V.22 (1200 bps) transmit data at 600 baud, but V.22bis modems use 4 bits per symbol while V.22 modems use 2 bits per symbol.


An acronym for Bulletin Board Systems. An electronic form of a bulletin board, containing graphics, sounds and text files that may be downloaded from the BBS to a personal computer. A BBS can be established on computers of all sizes, and can be accessed by PCs all over the world.


Also known as 'Bi-amping', driving a woofer and tweeter with different power amplifiers. A crossover is typically connected ahead of these power amplifiers.


In tape-recorder electronics, an ultrasonic signal that drives the erase head, and also is mixed with the audio signal applied to the record head to reduce distortion.

Bi-directional communications

The ability of a keyboard, sound module or drum machine to send and receive MIDI messages simultaneously from a computer or other device.

Bi-directional microphone

Also called a 'cosine microphone' or 'figure-eight microphone' due to the shape of its polar pattern, a microphone whose pickup pattern is sensitive to sound arriving at the front and behind the microphone. It rejects sounds approaching either side of the mic.

Binaural recording

A two-channel recording made with an omnidirectional microphone in each ear of a human or a simulated head for playback over headphones. The object is to represent sound as closely as possible at all frequencies.


Short for binary digit, the smallest unit of information in a binary number system. A bit may take on one of two values; either a 0 (off) or 1 (on).

Bits per second

Also known as 'bps', it indicates the maximum number of bits of data transferred per second, through a phone line, communication line, or MIDI cable.


A track or mix with weak highs; muffled as though a blanket was covering the loud speakers.


A sound with emphasized or excessive mid-bass around 250 kHz.


A sound or track with excellent reproduction of dynamics and reverberation, and a good low-frequency response. Also referred to as 'Spacious'.

Blumlein array

A stereo miking technique where two coincident bi-directional mics are angled 90 degrees apart (45 degrees to the left and right of center).


An unfocused sound with vague or poor stereo imaging. A sound or track with poor transient response.


An acronym for Broadcast Music International. BMI is one of several performing rights organizations which protect artists' and publishers' performing rights. BMI collects, handles and distributes royalties for member and publishers whose music has been played or performed publicly.


Also known as 'mixing console', a large unit having additional functions such as tone control, equalization, pan pots, channel assigns, monitoring sends, and control of signals sent to external signal processors.


A sound or mix with excessive bass response around 125 Hz.


Another term for low frequencies, usually below 125 Hz.

Bouncing tracks

When two or more separate tracks are mixed onto an empty track. The submixed tracks can then be erased, freeing them up for new music.

Boundary microphone

A mic designed to be used on a hard, reflective surface. The mic is mounted as close to the surface as possible so that direct and reflected sounds arrive at the microphone diaphragm in phase at all frequencies.


Also known as 'pumping', the undesired audible rise and fall of background noise that may occur with a compressor.

Boundary microphone

A mic designed to be used on a hard, reflective surface. The mic is mounted as close to the surface as possible so that direct and reflected sounds arrive at the microphone diaphragm in phase at all frequencies.


A mix having resonances as if the music were played from the inside of a box, perhaps due to a boost at 250 to 50o Hz.


Flute, clarinet, or sax recordings with audible breath sounds. Also, sounds with a good response the upper midrange and high frequencies.


A tonal balance with emphasized high frequencies or upper harmonics. Sounds having harmonics which are strong relative to fundamentals.


A sound or mix with high-frequency peaks or weak fundamentals; lacking roundness and fullness.


A storage or 'holding' area for data in the computer's memory until it can be processed.

Bulk tape eraser

A large electromagnet used to erase a whole reel of recording tape or an entire cassette at once.


Can mean the output of a mixer or submixer, or a channel that feeds a tape track, digital recorder, signal processor, or power amp.

Bus master

Located in the output section of a mixing console, a fader or knob that controls the output level of a bus.

Bus trim

Located in the output section of a mixing console, a control that provides variable gain of a bus, used in conjunction with the bus master for fine adjustment.


An unwanted edgy tone than can be present in an audio signal, containing harmonics of 60Hz.


A group of eight adjacent bits recognized as a single unit. A byte can represent characters, numbers, punctuation or any special codes. Bytes are to computers what words are to humans.


Commonly referred to as 'alignment', the adjustment of tape-recorder electronics and head alignment to achieve the best performance for the type of tape being used.


A slang word for headphones.


In a tape-recorder transport, a rotating post that contacts the tape (along with the pinch roller) and pulls the tape past the heads at a constant speed during recording and playback.


An acronym for Compact Disc Read Only Memory. A compact disc full of data such as programs, graphics, sounds, movies, etc., that can be read by a computer, but cannot be written to or changed.


A single path of an audio channel. Usually, each channel contains a different signal or one half of a stereo pair.

Chase lock

A synchronization system for audio equipment..


A track in which the vocalist sounds as if his chest was very large, due to an emphasis in the low-frequency response around 125 to 300 Hz.


Ability to play an instrument. To have great chops is to be technically or stylistically profient on a musical instrument.


A special effect in which a single sound source is made to sound like several, through the use of time delay and detuning. Delaying the input by a slowly varying time between 15 and35 milliseconds and mixing the dry input signal back in, a wavy, multiple-voice effect is achieved. It's also possible to feed a portion of the signal back into the input.


Free of noise, distortion, overhang, leakage. Not muddy sounding.


Easy to hear or differentiate; not distorted. Reproduced with sufficient high freqencies.


A component of a bass drum sound, the attack of the beater on the head of the drum.

Click track

Audio 'clicks' recorded on one track of a multitrack recorder, to indicate the tempo of the music on the tape. Clicks can be translated by certain devices into MIDI sync to control a sequencer, or can simply be used to keep musicians in time when overdubbing.


A track or mix which is too clean, lacking both warmth and an edge.

Close miking

A recording or sound reinforcement technique whereby the mikes are placed close to vocalists and to instruments or amplifier speakers. Close miking yields a great deal of presence and detail for the nearby sound source, while avoiding leakage from more distant sound sources. Most of today's popular music recordings use close miking techniques.

Coincident pair

Two separate mikes placed so that the microphone diaphragms occupy approximately the same point in space. The are mounted one directly above the other, and angled apart.


Non-uniform frequency response resulting in distortion of the tonal quality of the source.


A sound that is not true to life, perhaps due to an unnatural use of external processors. A mix that has a not-flat response with peaks and dips.

Comb-filter effect

The frequency response caused by combining a sound with its delayed duplicate. The frequency response displays a series of peaks and dips caused by phase interference. The peaks and dips look like the teeth of a comb, with very narrow, deep notches where signals are attenuated.

Combining amplifier

An amplifier in which the outputs of two or more signal paths are mixed together, to feed a single track of tape or hard-disk recorder.

Complex wave

A sound wave with more than one frequency component.


A sound, recorded track, or mix where the dynamics are restricted or narrowed.


The intentional reduction in dynamic range to increase sustain and/or add punchiness, caused by a the use of a compressor/limiter.

Compression ratio

Also known as 'slope', in a compressor/limiter, the ratio of change in input level (in dB) to the change in output level (in dB). For example, a 4:1 ratio means that for every 4dB change in input level, the output level changes 1dB.


A signal processor that reduces dynamic range by using automatic volume control. Also, an amplifier whose gain decreases as the input signal level increases above a pre-set point.

Condenser microphone

Also known as 'Cardioid microphone, a mike that works on the principle of variable capacitance to generate an electrical signal.


To prepare a program, modem, keyboard, or other electronic device to operate with specific characteristics.


Also known as a 'plug', the physical interface on cabling or equipment used to connect or hold together a cable and an electronic component that permits a sound signal or data to flow into an external destination, such as a mixing board or a computer.


Also known as 'mixing console' or 'board', a large unit having additional functions such as tone control, equalization, pan pots, channel assigns, monitoring sends, and control of signals sent to external signal processors.


A sound or track with poor reproduction of dynamics; overly compressed or pinched, with distortion at high levels.

Contact pickup

A transducer that contacts a guitar or other musical instrument and converts its vibrations into an electrical signal.

Continuous controller

A type of MIDI message intended to control dynamics (volume, modulation, etc.) or continually changing aspects of a performance. Continuous controllers allow enhanced musical expression for keyboardists and previously sequenced tracks, and also can be used to modulate effects device parameters such as reverb time or chorus depth,

Control room

The room in which the producer and engineer monitor and control the recording.

Control voltage

An electrical signal used to adjust the values of settings in analog circuits. If you send a specific electrical voltage to a module of a synthesizer (such as an ASDR envelope, you can specify what you want the module to do (perhaps lengthen the decay time).


A snare drum sound in which the sharp attack of the stick on the head of the snare has been boosted for emphasis at around 5 to 10 kHz.


A sound or track with an extended high-frequency response. A cymbal sound with sizzle and presence.


An electronic network that divides an incoming signal into two or more frequency bands. Crossovers can be active (with amplifying components) or passive (non-amplifying).

Crossover frequency

The single frequency at which both filters of a crossover network are down 3dB.


An acronym for the Canadian Standards Organization, that regulates and controls Canadian data communications standards.


Also known as 'Cue send', in mixer input module, a control that adjusts the amount of signal feeding the cue mixer which, in turn, feeds a signal to headphones in the studio. Also, a section of music or sound effects used in film or video production. The points in the film where the cues are played to sync with elements of the picture are called hits or cue points.

Cue mixer

A submixer in a mixer input module that takes signals from cue sends as inputs and mixes them into a composite signal that can be used to drive headphones in the studio.

Cue sheet

Typically used during the mixdown stage, a chronological list of mixer control adjustments and fader movements needed at various points in the recorded tracks. The list may have tape-counter or elapsed-time readings to indicate exactly when the adjustments should be made.

Cue system

A monitor system that allows musicians to hear themselves and previously recorded tracks through headphones.

Cutoff frequency

The designated frequency of a filter after which the sound is not allowed to pass. In a high-pass filter, a high cutoff frequency will be excessively trebly and bright, as no low frequencies will be present.
In a low-pass filter, a low cutoff frequency may be too muted and dark, as no high frequencies or overtones will be present.

Daisy chain

A term used when a group of modules (such as music modules or SCSI hard drives) are interconnected as follows: Module A's output is connected to module B's input; module B's output is connected to module C's input; module C's output is connected to module D's input, etc.


A sound or track with weak high frequencies; opposite of bright.


An acronym for Digital Audio Tape, a proprietary tape format used in DAT recorders. Similar to VHS VCR machines, DAT recorders use a helical scanning process to encode the digital audio. The digital audio is represented by streams of ones and zeros that are encoded onto the digital tape.


An acronym for Digital Audio Workstation, a stand-alone system of hardware and software which will allow the recording, playback, editing, and storage of digital audio.


Information that is processed or stored by a computer.


Abbreviation for decibel, a unit of measurement of audio level. dB is a logarithmic expression of a ratio comparing two sounds, such as how much louder one sound is than another, or how much quieter the level is at the output of a compressor than at the input.


Having very little or no reverberation; dry.


The segment of the envelope of a note in which the envelope goes from maximum to some mid-range level. Also, the decline in level of reverberation over time.

Decay Time

Also known as 'Reverberation time' or 'RT', the time it takes for reverberation to decay to 60dB below the original sustained level.


The unit of measurement of audio level. Ten times the logarithm of the ratio of two power levels. Twenty times the logarithm of the ratio of two voltages. Standard abbreviations using decibels include: dBV (decibels relative to 1 volt), dBu (decibels relative to 0.775 volt), dBm (decibels relative to 1 milliwatt) and dBA (decibels, A weighted).

Decoded tape

A tape that is expanded after having been compressed/coded by a noise reduction system, such as Dolby. The tape will have normal dynamic range.


A signal processor that removes musically excessive sibilant sounds ("sh" and "s" sounds) by compressing the high frequencies around 5-10kHz.


The time interval between a signal and its repetition. Processors that can delay a signal for anywhere from 10 milliseconds to 10 seconds are called digital delays or delay lines.


A sound with high frequencies up to 15 to 20 kHz, without peaks. Delicate sounds are also described as airy, sweet and open.


Also known as a 'Degausser', an electromagnet with a probe tip that can eliminate residual magnetism by touching it to elements of the tape path (such as tape heads and tape guides).


The audible sense of nearness and farness of recorded instruments or elements of a mix. We perceive close instruments to be those with a high ratio of direct-to-reverberant sound, and distant instruments to be those with a low ratio of direct-to-reverberant sound.

Designation strip

A strip of paper taped near console faders to indicate the instrument that each that each fader controls.

Design center

The portion of fader travel (usually marked), about 10-15dB from the top, where console gain is distributed for optimum headroom and signal-to-noise ratio. As a starting point in gain staging, each fader being used should be placed at, or close to, design center.


An alternate (England, Ireland) word for mixing console or board.


A mix or track in which it is easy to hear tiny details in the music; also described as 'articulate'. Characterized by sharp transient response and good high-frequency response.


An even distribution of sound in a room.


A circuit, processor, or other device using a binary numeric (1 or 0) system to represent and process information. A digital tape recorder converts the incoming analog audio signal into a stream of ones and zeros that are stored onto the tape. Upon playback, the series of numbers are converted back to a analog signal.

Digital audio

Audio signals converted into binary digits (ones and zeros) onto digital tape, CD-R or a hard drive, readable by a computer.

Digital recording

A recording system in which the audio signal is stored in the form of binary digits.

Digital-to-Analog converter

A circuit or chip that converts a digital audio signal into an analog audio signal.


To temporarily reduce the monitor volume by a preset amount.

Direct box

A device used for connecting an amplified instrument directly to a mixer mike input. The function of the direct box is to convert a high-impedance unbalanced audio signal to a low-impedance balanced audio signal.

Direct injection

Also known as 'DI', the process of recording with a direct box.

Direct output

Also known as 'Direct out', an output connector used to feed the signal of an instrument to one track of a tape recorder.

Direct sound

Sound traveling directly from the sound source to the microphone (or to the listener) without early or late reflections.

Directional Microphone

A microphone that has sensitivty in specific directions. Examples include unidirectional or bidirectional microphones.

Directivity factor

For a loudspeaker, a measurement of how much the speaker focuses sound in a given direction. Directivity is measured by taking the ratio of the average sound level in a circle around the speaker to the maximum sound level in front of the speaker (at a given distance and frequency).


A quiet or reverberant sound; opposite of forward.

Distant miking

Also known as ambient miking, a microphone placement technique where one or more mikes are located at a distance of at least several feet from the speakers or performers. Distant miking allows a greater area to be covered using fewer microphones than close miking. Distant miking will not generally provide the presence and detail possible with close mike placement.


An intentional desired, or unintentional unwanted, change in the audio waveform, causing a raspy or edgy sound quality.

Dolby tone

A reference tone recorded at the start of a Dolby-encoded tape, mainly for alignment purposes.


An effect in which an audio signal is combined with its 15-35 millisecond delayed replica. It can sound as if there are two identical voices or instruments playing in almost-perfect unison.

Drop frame

In video production, a mode of SMPTE timecode which causes the timecode to match a regular clock. Once every minute, except for the tenth minute, frame numbers 00 and 01 are dropped.

Drop In/Out

Alos known as 'punch in/out', a feature of a tape or hard-disk recorder that permits insertion of a corrected musical part into a previously recorded track by going into and out of record mode at designated time.


During playback of an analog tape recording, a momentary loss of high frequencies caused by loss of contact of the tape from the playback head due to dust, tape-oxide deterioration, etc.

Drum machine

A device (stand-alone or within a synthesizer) capable of producing drum-like sounds or digital recordings of real drum sounds.


A sound or track having little or no audible reverberation or other effects. Lacking spaciousness. Also, a close-sounding signal that has not been processed by a reverb or delay effect. A sound with an overdamped transient response.

DSP board

An acronym for Digital Signal Processing Board, which may encompass both audio and video processing, that manipulates signals internally within a custom chip in the digital domain.


A sound or track with weak high frequencies; opposite of bright.

Dynamic microphone

A type of mike generating electricity when sound waves cause a conductor to vibrate in a stationary magnetic field. Ribbon mikes and moving-coil mikes are two examples of dynamic microphones.

Dynamic range

The difference (usually measured in dB) between the loudest and the softest sounds in a song or track.

Earth ground

A connection to the physical ground or 'earth'. This connection can be made either to a cold water pipe or a special copper rod driven into the soil.


A delayed repetition of a sound or signal, usually at least 50 milliseconds after the original sound.

Echo chamber

A hard-surfaced room or enclosed space containing a microphone placed at a distance from a loudspeaker. When sound is played through the speaker, the mic will pick up reverberation from the room.

Echo return

Also known as 'Echo receive' or 'Effects return', a control on the mixing console that adjusts the amount of signal received from an echo unit or reverb unit. The echo return signal is combined with the program buss signal.

Echo send

Also known as 'Effects send', similar to an auxiliary send, the control on a mixer that determines the level of channel signal sent to a dedicated echo unit or reverb device.


A sound or track with too many high frequencies resulting in a overly trebly sound. Also, a sound with harmonics which are too strong relative to the fundamentals, resulting in distortion and/or a raspy sound.


To modify, add, or delete sections or parts from a song, track, sample, MIDI track, etc.

Editing block

A metal block that secures the magnetic tape to assure accurate splicing/editing cuts.


Computer programs specializing in synthesizer sound editing and patch organization. The librarian retrieves sound parameter data from synthesizers, and the editor permits the altering of sounds in the computer.


An acronym for Electrically Erasable Programmable Read Only Memory. A computer chip that can be loaded with data (sound samples, program patches, etc.) and later erased (with an electrical voltage) and loaded with updated information.


A generic term for the enhancement or modification of sound by the use of signal processors such as delay, echo, chorus, reverberation, pitch shifting, etc.

Effects buss

A buss that feeds external or internal (to the mixing board) effects devices and signal processors.

Effects mixer

A submixer in a mixing console that combines signals from effects sends and directs the mixed signal to the input of another effects device.


In a loudspeaker, the ratio of acoustic power output to electrical power input.


An acronym for the Electrical Industries Association.

EIA rating

A specification of microphone sensitivity that states the microphone output level in dBm into a matched load for a given sound pressure level or SPL. The formula is SPL + dB (EIA rating) = dBm output into a matched load.

Electret condenser microphone

A type of condenser mic where the electrostatic field of the capacitor in generated by an electret, a substance which permanently stores an electrostatic charge.

Electrostatic field

The force field between two conductors charged with static electricity.

Electrostatic interference

The undesired presence of an electrostatic hum field in signal conductors.

Encoded tape

A tape having a signal compressed by noise reduction.


The rise and fall in amplitude (volume) of a note. The envelope of a note consists of the four stages: attack, decay, sustain, and release.

Envelope generator

Also known as a 'Contour generator', a device, circuit, or software algorithm that generates an ADSR envelope.


An acronym for Erasable Programmable Read Only Memory. A computer chip that can be loaded with data (sound samples, program patches, etc.) and later erased (with an ultra-violet light) and loaded with updated information.


Often abbreviated to 'EQ', the adjustment of specific frequencies (bands) to alter the tonal balance or to remove unwanted frequencies.


A circuit with the ability to change the frequency response of a signal passed through it.


To remove an audio signal from magnetic tape by applying a varying magnetic field that randomizes the magnetization of the magnetic particles on the tape.

Erase head

A head in a tape recorder that erases the signal from tape.


A sound that is clear but very close to being edgy, with an emphasis in the frequency response around 100 kHz or higher.


A signal processor that increases the dynamic range of a signal.

Fade out

To slowly and smoothly reduce the level of the last few seconds of a track or recorded song, by gradually pulling down the fader.


A linear or sliding volume control, used to adjust audio level.


A sound which has been slightly distorted by means of analog tape saturation or tube distortion, yielding a warm, full sound. Also, a sound which is spatially diffuse, accomplished by panning a signal hard left in the stereo spectrum, then delaying the signal slightly and panning the delayed signal hard right.


An acronym for the Federal Communications Commission, the U.S. government agency responsible for regulating and approving data communications devices, telecommunications devices and the public airwaves.


The act of sending a signal to some device, channel input or bus. A feed can also be an output signal send to a device, bus or input.


The return of a portion of the output signal to a device's input. A common source of feedback is sending the output of a guitar amp's speaker into a guitar's pickups, by stepping close to the amp.

Feed reel

The left-side reel on a cassette tape or tape recorder that unwinds during recording or playback.


A circuit that attenuates or removes frequencies from a sound or waveform above or below a certain frequency. Filters can be used to reduce unwanted noise above or below the frequency range of a voice or instrument. One type of filter, a bandpass filter, allows the frequencies within a specified range to pass, while a notch filter inhibits the frequencies in a specified range. Even MIDI data can be filtered, using a MIDI data filter, to remove specified messages (pitch bend, modulation) from the MIDI data stream.


An effect in which a delayed signal is varied between 0 and 20 milliseconds of delay and combined with the original signal. The resulting swishing, hollow sound is reminiscent of a jet passing overhead. Usually a variable comb filter is used to produce the flanging effect.

Fletcher-Munson effect

The psycho acoustical phenomenon in which the subjective frequency response of the human ear changes with the audio level. The result of this effect is that a sound played at a lower relative volume appears to lose both low and high frequency response.


To disconnect from ground.


A rapid and periodic variation in tape speed.

Flutter echoes

A rapid series of echoes occurring between two parallel walls.


Magnetic lines of force.


The measure of the flux density of a magnetic recording tape, per unit of track width.


A feature of a sync box that allows it continue to generating reliable MIDI sync even when a bad sync stripe is being read from tape.

FM synthesis

A type of synthesis based on complex combinations of sine waves.


A sound which is easy to locate in the stereo field, due to a small spatial spread.


Also known as 'FB' or 'Cue system', a monitor system that permits musicians to hear previously recorded tracks, along with their live performance, through headphones.


Film term used to describe the process of triggering the proper sound effect at the precise time. Usually the trigger time is specified as a SMPTE time given in hours, seconds, minutes, and frames.


A sound or track which sounds close to the listener, often described as an intimate sound. Also, a sound with a boost in the frequency response at about 2 to 5 kHz.


Measured in hertz (Hz), the number of cycles per second of a sound wave or audio signal. A high-frequency sound (example, 12,000 Hz) has a high pitch, and a low-frequency sound (example, 200 Hz) has a low pitch.

Frequency response

The range of frequencies that an audio device will reproduce at an equal level, within a tolerance, such as +/- 2dB.


An acronym for Frequency Shift Keying. FSK is an older method (pre-MIDI) of keeping drum machines and tape recorders in sync. An audio tone would be generated by a drum machine or sequencer and recorded onto one track of the multitrack tape recorder. The tone would alternate between two distinct frequencies and the rate of alteration would correspond to the tempo of the music.


When used to describe a sound's tonal balance, complete or near-complete reproduction of low or fundamental frequencies, with adequate level around 200 Hz. A sound with strong fundamental frequencies relative to harmonics. Female voices tend to sound full around 250 Hz, whereas male voices sound full around 125 Hz.


The lowest frequency in a complex sound wave.


Also known as 'Amplification', the ratio between the input voltage and the output voltage, or between the input power and the output power. Gain is usually expressed in decibels.


The thin break in the electromagnet that contacts the tape in a tape recorder head.


To shut down a signal when its volume falls below a given value. Also a short name for 'Noise gate, a processor used to eliminate noise between notes.

General MIDI

A superset of the MIDI standard that describes sound mappings in MIDI instruments. Music written and sequenced for General MIDI should play back with the same instrument sounds on any General MIDI (GM) sound source.


A copy of a tape. An original master recording is referred to as a first generation tape. If you make a copy of the original master tape, you have a second generation tape. Copy the second generation tape and you have a third generation tape. With audio tape, each generation suffers degradation through increased noise and hiss. Digital tape generations created in the digital domain generally experience little or no degradation.

Generation loss

The degradation of signal quality that occurs with each successive generation of audio tape. The generation loss is usually in the form of increased hiss, distortion and noise.


A sound having harmonics in the upper midrange and high frequencies which are not boosted, or may be slightly attenuated or cut. Gentle is similar to mellow.


Sound which is too bright, trebly or edgy.


Sound which is too bright and has an unpleasant high frequency response.


Short for 'go-between', a portable partition used when recording to prevent sound leakage between adjacent microphones.


Sound which suffers from harmonic distortion or has been digitally converted using a low sample rate or inferior A/D converters. It has the overall effect of making music sound like it has been separated into 'grains' of sound, lacking warmth and fluidity.

Graphic equalizer

Also known as graphic EQ, a type of equalizer with a horizontal row of faders; each fader's position indicates the frequency response or frequency correction of the equalizer within a preset frequency range; viewing all faders gives a graphic representation of the desired frequency response. Graphic equalizers can be used as a special effect or to flatten monitor speaker response for the current listening environment.

Groove quantize

A sequencing quantization method that uses a performance template instead of an absolute value to alter the rhythmic characteristics of a sequence. Usually involves preset grooves (i.e. funk, swing, etc.) or uses one rhythmic sequence as a model for quantizing another sequence.


The zero signal reference point for a group or system of audio components. Also, a short term for 'Earth ground'.

Ground buss

A heavy plate (typically copper) used as a common connection point to which audio equipment is grounded.

Ground loop

A loop formed when unbalanced circuits or components are connected together via two ground paths (the connecting cable shield and the power ground), causing unwanted hum in the system.


The act of connecting audio or electrical components to ground. When components are grounded correctly, there is no voltage difference between equipment chassis.


Also known as 'Submix', a smaller mix of tracks or instruments feeding a larger or master mixing board. Typical groups include a vocal group, keyboard group and percussion group.


As applied to the bass guitar, a boost or peak in the frequency response around 600 Hz.


A sound or track with an abundance of harmonic distortion.


An extension to the General MIDI standard that describes tone editing parameters, effects and an enhanced instrument set.

Guard band

The space or extra track between tracks on a multitrack tape machine or tape head, whose purpose is to prevent crosstalk between recorded tracks.

Haas effect

Also known as the precedence effect, this effect describes our ability to perceive the location of a sound source based on the relative level and arrival time of the sound in each ear. This phenomenon was first discovered by Helmut Haas.


An audio tape track recorded on half the width of the recording tape. A half-track recorder records two tracks concurrently in the same direction for stereo recording.


A sound or track which has too much upper midrange (around 3 kHz) combined with a good transient response.

Hard-disk recording

Recording audio digitally to a computer hard drive or to a dedicated hardware device.


An overtone at a frequency that is a whole number multiple of the fundamental frequency.


Sound which has peaks in the upper midrange area (about 2 to 6 kHz) of the frequency response. Harshness can also be caused by too much phase shift from the low-pass filter in a digital recorder.


In a tape recorder, the electromagnet that plays back what has been recorded on tape, records audio onto tape, or erases signals already on the tape.

Head gap

Also known as simply 'Gap', The thin break in the electromagnet that contacts the tape in a tape recorder head.


A transducer, worn on the head, that covers or surrounds both ears which converts electrical audio signals to sound waves, used for monitoring or recreational listening.


A margin of audio safety between the current signal level and the maximum signal level possible without introducing distortion. Headroom is usually measured in decibels. When referring to a tape recorder, headroom is the difference between the standard operating level (0VU on the VU meter) and a level causing 3 percent total harmonic distortion. You can increase high frequency headroom by recording audio tape at higher speeds.


A music track or sound with good low-frequency response below 50 Hz. It suggests an object of great mass or power, such as a jet or thunder.


Vibrations or cycles per second, abbreviated 'Hz', a measurement of the frequency of a vibrating object. If you play the open A string on a concert-tuned guitar, the string's tone is at 110Hz, which is 110 vibrations per second. The human range of frequency perception, on average, is roughly 20 Hz to 20,000 Hz.

High-pass filter

Also known as a 'Low-cut' filter, a filter that passes frequencies above a given frequency and cuts frequencies below that same frequency.


A sound, recorded track or mix which has too much reverberation or a dip in the midrange frequency response. Also, too much spaciousness or room ambiance.


A track or entire mix which sounds the way your voice does if you cover your mouth with an object. Honkiness can be caused (or achieved) by a peak in the frequency response around 500 to 700 Hz.


Recording signals to tape at a high level, causing a mild distortion or tape saturation to occur, used as an effect. Hot can also refer to the conductor in a mic cable which has a positive voltage on it at the moment sound pressure moves the diaphragm inward. Hot is also used to describe a chassis or circuit that has a potentially harmful voltage on it.


An undesired low-pitched sound (at around 60 Hz and its harmonics) that can be heard along with the audio signal.

Hypercardioid microphone

A directional mic with a polar pattern that has 12dB attenuation at the sides, a 6dB roll-off at the rear, and two points of maximum rejection at 110 degrees off-axis.

Idler wheel

Also known as a 'Pinch roller', in a tape recorder transport, the rubber wheel that traps the tape between itself and the capstan, so that the capstan can move the tape forward.


An acronym for International MIDI Association. A member-supported MIDI information network.


The illusory sound field located between two stereo speakers.


The complex sum of resistance and reactance. The opposition or resistance of a circuit to the flow of alternating current.


The connection going into an audio device or computer. In a mixing board, a connector for a microphone or other signal source.

Input module

In a mixing board, the group of controls affecting a single input signal, possibly including a fader, equalizer, trim, effect sends, cue send, solo, and bus assignment controls.

Input section

Refers to all of the input modules of a mixing board.


An abbreviation for Input/Output for data flow.


An acronym for International Standards Organization. An international organization that controls data communications standards, as well as a number of other standards.


A receptacle-type connector for audio signals into which a plug or other input is inserted. The plug is the 'male' connector and the jack is the 'female' connector.

Jam sync

The ability of a sync box to continue to read SMPTE time code even when the time code on the tape is corrupted.

Keyboard controller

A keyboard instrument that transmits MIDI data, but has no onboard sounds.

Keyboard workstation

A keyboard that typically includes an internal sequencer, effects processor, and multitimbral sound module.


A unit of measurement prefix meaning one thousand, and commonly abbreviated 'k'. A kilogram is a weight of one thousand grams and 1 kilohertz (1 kHz) is a frequency of one thousand hertz.


Describes the process of manually splicing leader tape between program material on an audio tape.

Leader tape

Plastic or paper tape (without the oxide coating) used for spacing or absolute silence between takes or songs.


Also known as 'Bleed' or 'Spill', the overlap of an instrument's sound into another instrument's mic.


An abbreviation for 'Live End, Dead End', referring to acoustical treatment in the control room, in which the front half of the control room (around the mixing board) is deadened with acoustical tile to prevent early reflections from coloring the sound, while the back section of the room is left 'live', to reflect sound back to the mixing area.

LED Indicator

A recording level indicator using one or several light emitting diodes, or LEDs.


The degree of strength of an audio signal measured as power, voltage, or sound pressure level.

Level setting

Adjusting the amount of signal sent to an input channel of a mixer or to the record head of a tape recorder. The amount of signal is usually monitored visually through the use of an LED meter, VU meter, or other indicator.


A signal processor whose output is constant when the input signal exceeds a designated level. You can make a compressor into a limiting device by setting the compression ratio to 10:1 or greater, and by setting the threshold just below the distortion point of the device following the compressor in the signal path. Limiting is most useful for preventing damage to hearing (in-ear monitors), or distortion from signal peaks or transients.

Line level

In semi-pro or home devices (unbalanced), a signal whose level is at -10dBV (0.316 volt). In professional gear (balanced), a signal whose level is at +4dBm (1.23 volts).


Occurring in person, or in real time. Also applies to sound which has reverberation.

Live recording

A recording made at a club, concert hall, stadium, or other venue with an audience. Also refers to a recording made with a band or group playing all together, without the use of overdubbing.


The ability of the human ear and brain to discern the direction of a real or pseudo sound source.


A transducer that changes electrical energy (the signal source) into acoustical energy (sound waves) that you can hear.

Low-pass filter

Less commonly known as a 'High-cut filter', a filter that does not alter frequencies below an established frequency and cuts frequencies above that same frequency.


Bass sounds or other low frequency sounds.

Magnetic recording tape

A recording medium made of magnetic particles suspended in a binder and coated on a long strip of thin plastic.


To cover up one sound with another sound. To make it difficult or impossible to hear a sound by playing another sound in the same frequency range at a louder volume.


When syncing two devices together, the controlling device becomes the master and the other device becomes the slave. The slave only responds to commands from the master; it does not also control the master. When syncing a sequencer to tape, the tape deck usually acts as the master and the sequencer becomes the slave.

Master fader

A volume control that adjusts the level of all program busses at the same time.

Master tape

The final mix or completed tape used as the duplication source for CDs and tapes.


An acronym for Modular Digital Multitrack. Examples include the original Alesis ADAT and Roland DA-88. MDMs typically allow multiple machines to be connected to increase the number of tracks available.


a sound or recorded track with reduced high frequencies, not edgy.


Integrated circuit chips used to temporarily or permanently store digital data, such as computer data or digital audio.

Memory rewind

A function of some tape recorders to automatically rewind the tape to a designated position. The tape recorder stores the tape counter position in memory and will return to that position when the memory rewind button is pressed.


A unique ability of hard disk recording systems. Similar to audio bouncing, except it is not necessary to have open, available tracks. For example, in a four track system, all four tracks can be mixed to two, thus freeing up two additional tracks.


A device that indicates signal level strength. Meters are also used to show current, voltage and resistance.


An abbreviation for microphone. Also, the act of picking up or recording an audio signal with a microphone.

Mic level

The level or voltage of a signal typically produced by a microphone, about 2 millivolts.


A device that converts sound into an electrical signal. Common microphones include cardioid, ribbon, stereo, omnidirectional and condenser.

Microphone technique

The choosing and placing of microphones to pick up sound sources in order to achieve the desired sound.


An acronym for Musical Instrument Digital Interface. A method of communication between computers, mixers, musical instruments and accessories consisting of a set of messages that can represent musical performance, mixing movements, or patch data. If a keyboard is hooked to a computer, using MIDI, a computer sequencing program is capable of recording a musical performance.

MIDI channels

Electronic "highways" for communicating with MIDI instruments. The original MIDI spec called for 16 separate channels. However, multi-port devices now exist that allow for more channels.

MIDI controllers

Performance characteristics within the MIDI standard. Characteristics include volume, modulation, panning, etc. Most sequencers allow recording and editing of controller data.

MIDI cue sheet

A list of MIDI events that have to be transmitted at specific times. The MIDI events typically consist of note-ons, controller changes, or program changes. The times as usually specified as SMPTE times that are given in hours, minutes, seconds, frames, and sometimes sub frames (1/80 of a frame).

MIDI merging

When two individual MIDI data streams are brought together and forwarded as a single MIDI event stream. For example, the two data streams might be from two keyboards, or a single keyboard and a foot controller, and you may wish to record the sum of the two into a sequencer.

MIDI patch bay

A patch bay wired with MIDI cables that controls the routing of messages to and from all MIDI devices in a studio.

MIDI time code

Also known as 'MTC', it is the MIDI equivalent to SMPTE. SMPTE timing data can be converted to MIDI time code messages that can be sent to a sequencer for synchronization purposes.

MIDI timing byte message

As set forth in the MIDI standard, one MIDI timing byte is sent 24 times every quarter note. Therefore, if the tempo of a sequenced song speeds up, MIDI timing data is sent at a faster rate. MIDI timing bytes contain no indication as to where in a song they occur; they are similar to the tick of a metronome. With MIDI, location within a song is given by a song pointer message.


An older, less-used abbreviation for microphone. Also, the act of picking up or recording an audio signal with a microphone.


A metric system prefix meaning one thousandth, commonly abbreviated as 'm'. One millisecond is 0.001 of a second.


To combine two or more audio signals or MIDI data streams into a single audio signal or data stream. A stereo mix combines two or more audio signals into a left-right pair of audio signals. Mix can also refer to the control on an effects processor that controls the amount of effect versus the amount of unprocessed signal sent to the output of the processor.


The process of playing pre-recorded tracks (audio or digital) and/or 'virtual' MIDI tracks through a mixing board combining the signals, and sending the result to another tape deck or digital recorder. A typical mixdown is done in stereo.


A device that combines and controls the levels of individual audio signals. A MIDI mixer, combines, merges, or filters the data streams of two or more MIDI cables and sends the resulting MIDI stream down another MIDI cable.

Mixing console

Also called a 'Mixing board', a large mixer with additional functions like EQ, panning, effect sends, soloing, muting, trim, etc.


An acronym for MIDI Manufacturers Association, a manufacturers trade organization that develops technical standards for MIDI.


An acronym for MIDI Machine Control, a way for software to remotely control hardware (tape deck transports) via MIDI. Tape decks must support MMC with a MIDI to tape transport control interface.


A data communications device whose name derives from its function: modulator/demodulator. The modem converts digital signals from a computer to analog signals (modulation) for transmission over telephone lines, and vice versa (demodulation).


Listening or monitoring with one ear.


A pair of stereo loudspeakers in a control room or a set of headphones, used to assess sound quality and balance. On stage, a floor mounted loudspeaker with a mix appropriate to the musician in front of the speaker. For example, if a singer wishes to have a monitor mix which is bass-heavy, their monitor can deliver a mono mix which includes boosted bass frequencies.


Listening to an audio signal with a monitor.


An abbreviation for monophonic.


Refers to a single channel of audio.


A stereo program which can be safely combined into a single channel of audio without experiencing phase cancellation, or altering the tonal balance or frequency response.

Moving-coil microphone

A type of dynamic microphone in which the conductor is a coil of wire moving in a fixed magnetic field. The coil is attached to a diaphragm which vibrates when sung or shouted into.


Sound which lacks clarity, exhibits a smeared time response, or has weak harmonics. Also used to describe a mix where the individual instruments are overlapping each other's frequency range.


A track or mix which sounds as if the loudspeakers were covered with a blanket. Characterized by a weak upper midrange or weak high frequency response.

Multiple-D microphone

A type of directional microphone having minimal proximity effect due to multiple sound path lengths between its front and rear sound entry points.


A signal processor or type of computer capable of performing several different processing functions. In the case of the computer, the functions are done simultaneously; in the case of the signal processor, the functions are performed in series, yet appears to a musician as if all functions or effects are happening at the same time.


Capable of producing different sounds (timbres) at the same time.


A tape recorder or digital recorder having more than two tape tracks.


To silence an input signal on a mixing board (usually by pressing a mute switch) by severing the connection between the input module's output from the direct out and the master out. Muting is used to help create quieter final mixes by eliminating noise from temporarily or permanently unused tracks.


An acronym for the National Association Of Music Merchants, a not-for-profit association which provides a variety of tangible services to retail and commercial members of the music products industry.


A vocal sound that seems as if the singer has his nose pinched, which can be caused by the mic positioned too close to the singer's mouth. A nasal, or honky instrument sound can be caused by a peak in the frequency response around 600 Hz.


A stereo miking technique where two mics are angled apart in a symmetric fashion, and spaced a few inches apart.

Near-field monitoring

A monitor speaker arrangement in which the speakers are situated very close to the listener, to reduce the effect of the room acoustics when tracking or mixing.


Unwanted sound, such as hum from the power system or hiss from a tape recorder.

Noise reduction system

A device used to reduce or nearly eliminate hiss from the signal introduced as a by-product of the recording process. When used with tape-based systems, certain processors encode the tape, and decode it again on playback. Single-ended noise reduction processors simply reduce noise without encoding.

Noise gate

A device or circuit used to reduce or eliminate noise between notes or musical phrases.

Non-destructive editing

Edits that do not alter primary recordings. Typically these edits, if they are performed on a hard-disk recording system, are stored as new files, allowing for multiple levels of undo.


A process that increases the overall level of an audio recording to maximize its output and reduce system noise.


Also known as a 'laptop', a portable, battery-operated, personal computer.


The interval between any two frequencies where the upper frequency, 880 Hz for example, is twice the lower frequency, say 440 Hz. The frequency of the open A string on a guitar is at 440 Hz and the frequency of the note A, one octave up on the A string 12th fret, is at 880 Hz.


Not directly in front of a microphone or speaker, the axis being the center of the mic or speaker.

Off-axis coloration

The alteration of tone quality for sounds arriving off-center to the microphone.

Omnidirectional microphone

A mic that is equally sensitive to sounds coming from all directions.

On-location recording

A recording made outside the studio, in a club, concert hall, or other venue with a live audience.

Open tracks

On a multitrack tape or digital recorder, the unused tracks.

Outboard equipment

Signal processors or other effect devices that are not internal to the mixing board.


A connector in an audio device from which the signal exits into a cable. An output on a MIDI device is called a MIDI output, or MIDI out, and is connected to another device's MIDI in.


An entire recorded performance or a portion of a recorded performance that is to be discarded and not used.


To record a new musical part on an unused track while listening to the previously recorded tracks.


The continuation of a signal at the output of a device or mixer after the original input signal has faded.


The distortion resulting from a signal exceeding a input's maximum input level.


A frequency component that is higher than the fundamental frequency in a complex sound wave.


An acronym for Performing Artists Network, an information network that offers a subscription and allows you access to the PAN bulletin board information system.


A kick drum sound characterized by a boost between 300 and 900 Hz.

Parametric EQ

Also known as parametric equalization, a type of equaliztion where the range of frequencies affected by cuts and boosts in level is adjustable.


A set of parameters and their values on an effect unit or synthesizer that create a specific sound. Patch originally referred to the cables, or patch cords, that were used to connect components from early synths; it now refers to a named or numbered set of parameters that can usually be altered and saved.

Patch bay

A unit that allows the user to reconfigure audio equipment connections without having to access to the rear of the unit. All inputs and outputs to the audio equipment are connected to the back of the patch bay, and patch points are provided at the front of the unit to redirect audio using patch chords.

Peak amplitude

On a graph of a sound wave, the sound pressure of the waveform peak. The amplitude of a sound wave when measured using a meter is 0.707 times the peak amplitude.


A sound that sounds out of phase, resulting in a directionless quality and/or a flanging effect. It can be caused by picking up sound from more than one microphone, or when recording an instrument using a mic close to a surface.


A strident, shrill sound which is hard on the ears. A piercing sound usually has peaks in the frequency response around 3 to 10 kHz.


A sound or track with a very narrow frequency range, or a sound with peaks in the frequency response in the midrange or upper-midrange area.

Pink noise

A mixture of all frequencies between 18Hz and 1kHz.

Pitch to MIDI converter

A device that detects the pitch from a microphone or guitar and translates the information into corresponding MIDI messages (note on, pitch bend, etc.).

Polyphonic synth

A musical instrument in which two or more independent voices are capable of sounding at the same time.


The maximum number of notes (simultaneous pitches) a unit (keyboard, sound module, etc.) can produce at the same time.


A sound with good bass response below about 60 Hz.


An acronym for Pulses Per Quarter Note. Sometimes abbreviated at PPQN.


The aural characteristic of feeling that the instrument is in the listening room, or the feeling of being "up front". You can usually achieve presence or clarity with most instruments by boosting the response around 5 kHz, or between 2 to 5 kHz for low instruments, such as bass and kick drum.

Presence range

The area of the audio frequency spectrum which affects the perceived presence of the sound.


A music track or sound sample with a bump or peak in the response around 500 Hz.


A sound or track with a good reproduction of dynamics, having good transient response. Bass sounds can be boosted at 200 Hz, and other instruments can be boosted at around 4 to 6 kHz to add punchiness.


The correction of rhythms in a MIDI sequence.


A wooden or metal cabinet with standardized dimensions and hole spacings used to mount audio equipment. The rack holes are spaced exactly 19 inches apart, side to side.

Rack mount unit

Any unit that conforms to the 19-inch E.I.A. (Electronic Industry Association) specifications for rack hole alignment.

Radio frequency interference

Also known by the abbreviation 'RFI', the presence of electronic waves at AM or FM frequencies in audio cables or equipment, causing unwanted noise in the audio signal.


An acronym for Random Access Memory, memory that can be read from and written to (as opposed to ROM). Data stored in RAM is lost when the power is turned off.


A harsh sound, like a rasp. Also used to describe vocals with excessive sibilance or sounds with a piercing quality, which can be caused by peaks in the frequency response at about 6 to 7 kHz.

Real time recording

Recording notes or other MIDI performance data into a sequencer at the tempo at which it was performed. Also, recording and mixing a performance directly to two-track tape or lacquer disk.


To store a visual, MIDI, or audio event in a permanent form.

Record equalization

Adjustments to specific frequencies applied to the signal by a tape recorder to compensate for certain frequency losses.

Record head

The head in a tape recorder that puts the audio signal on tape by magnetizing the tape particles in a pattern corresponding to the signal.

Reflected sound

Those sound waves that reach the listener or audience after being reflected from one or more surfaces (walls, ceilings, floors, etc.)


The process of taking incoming SMPTE, which may have shaping problems or dropouts, and generating new, perfect SMPTE, that is perfectly time-locked to old SMPTE. This process is called regeneration because instead of being generated for the first time, the SMPTE is being "regenerated" from another SMPTE source. Also, the feeding of the output of a delay device back into its input to create multiple echoes.


User-defined sections of audio that can be edited, looped, or processed.


The final portion of a sound's envelope in which the sound falls from its sustain level back to silence.

Release time

Also known as 'Recovery time', the time it takes for the gain to return to normal from its processed level in a signal processor. Also, pertaining to a synthesizer, the time it takes for the sound to go from its sustained level to silence.


To do another mixdown with different edits or different mixing parameters.

Remote recording

Also known as 'On location recording', a recording made outside the studio, in a room, club, or other venue where live music is usually performed.


The opposition of a circuit to the flow of current . Resistance is measured in ohms, and can be calculated by dividing the voltage by current.


A function on a tape recorder that rewinds the tape to the zero counter position on the tape. The zero counter position can be anywhere on the tape, since it is established whenever the user resets the counter.


Often shortened to 'Reverb', the persistence of sound in a room or other space, even after the original sound has ended, caused by many sound reflections that decrease in intensity with time. The reflections, or echoes, are so closely spaced in time as to merge into a single continuous sound. The reflected sound eventually decays completely by being absorbed into the surfaces of the room. Reverberation in modern recordings is commonly generated by signal processors, rather than acoustically.

Reverberation time

The time it takes for reverberation to decay to 60dB below the original level. Reverb time is commonly abbreviated to RT60, and is usually measured at 500Hz.

Reverse echo

An echo that precedes the sound that caused it, building up from silence into the original sound. Reverse echo can be created either electronically (using a signal processor), or by reversing a tape track, adding the echo effect, and reversing the tape back to the original direction.

Rhythm tracks

The generic name for the recorded tracks of the rhythm instruments (rhythm guitar, bass, drums, keyboards).

Ribbon microphone

A dynamic mic in which the conductor is a long metallic diaphragm (ribbon) suspended in a magnetic field.


Tracks or sounds having euphonic distortion made of even-order harmonics (harmonics sometimes added by aural exciters). A rich sound is also frequently described as 'full'.

Ride gain

To manually adjust the volume of a microphone or mixer channel,. raising the fader when the signal is quiet, and lowering the fader when the signal is loud, in an attempt to reduce the dynamic range of the signal. Using a compressor is an automatic way to solve the same problem.


A common word for a musical motif or phrase, especially popular with guitarists and keyboard players.


Standardized 6 pin telephone interface in North America. Also used in most telecommunications equipment worldwide.


An acronym for Read Only Memory, memory that can only be read and cannot be used for temporary storage. ROM retains its contents even when power is turned off.


A sound with a high-frequency rolloff or dip. A track or sound which is not trebly or edgy.


Standardized 6 pin telephone interface in North America. Also used in most telecommunications equipment worldwide.

Safety copy

A duplicate of the master tape or disc, to be used if the master tape or disc is lost or damaged.


The recording of a short sound event into a sampler or computer. The audio signal is converted into digital data representing the signal's waveform, and is then stored onto magnetic disk for editing and playback.


Overload of a magnetic tape. The saturation point is the point at which an increase in magnetizing force does not cause a corresponding increase in magnetization of the tape oxide particles.


An acronym for Small Computer System Interface, a communications system that loads massive amounts of sound data into samplers, or data into computers at extremely high speeds, then returns the data back out to removable media hard disks and optical drives for storage.

Scratch vocals

Vocal performances that are typically done as the rhythm instruments are being recorded so that the musicians can get a feel for the song and keep track of where they are in the tune. If the scratch vocals are recorded, they can contain leakage from other instruments, in which case they are usually deleted or erased. At times, the scratch vocals are so good they are kept as the main vocal tracks of the song.


An acronym for Sample Dump Standard, a standard for transferring samples via MIDI.


The output of a microphone in volts for a given input in sound pressure level. Sensitivity can also mean the sound pressure level (SPL) a loudspeaker produces at one meter when driven with one watt of pink noise.


A dedicated device that records a series of synthesizer note parameters (via MIDI) into a storage device for subsequent editing and playback. Or, a software program that records note data onto a computer's disk drive. Most sequencers can also record system exclusive messages, MIDI mixer or recorder data, and store bulk dumps of parameter data from signal processors. During playback, the sequencer triggers the synthesizer sound generators and sample playback devices as well as reproducing mixer movements and controlling signal processing programs and parameters.


A excessively trebly or edgy sound, with too many high frequencies. It can also be used positively to describe a tight sound with good low-frequency transient response and detail.

Shelving equalizer

An equalizer that applies a constant boost or cut to a signal either above or below a chosen frequency. The resulting waveform shape resembles a shelf.


A conductive enclosure (usually metallic) around one or more signal conductors, used to keep out electrostatic fields that can cause hum, buzz, or other noise.

Shock mount

A suspension system that mechanically separates a mic from its stand or boom, preventing the transfer of vibrations.


In a vocal recording, excessive peaks in the frequency response in the 6-10kHz range, due to an overemphasis of 's' and 'sh' sounds. Sibilance can usually be minimized in a recorded track through the use of a signal processor known as a de-esser.


A vocal track with excessive or exaggerated 's' and 'sh' sounds, due to a peak in the frequency response around 6 to 10 kHz. Also known as 'essy'.


A varying electrical voltage that represents sound.

Signal path

The route a signal travels from input to output in a piece of audio gear or in an audio system.

Signal processor

A device that is used to deliberately alter a signal in a controlled manner. Examples of signal processors include reverberation units, digital delays, flangers, equalizers, etc.

Signal-to-Noise ratio

The ratio in decibels between an audio signal voltage and noise voltage. A device with a low signal-to-noise ratio is considered noisy, and a device with a high signal-to-noise ratio is considered clean or quiet, with little background noise accompanying the signal.

Sine wave

The wave form of a sound containing just a fundamental frequency without overtones, commonly referred to as a "pure tone".

Single-D microphone

A type of directional mic having an identical distance between its front and rear sound entry points.


A noise reduction system that only needs to be placed at the output end of the signal chain. Single-ended noise reduction does not involve encoding of the signal, and therefore does not need to be decoded by a device receiving the signal.


When describing vocals, a track with excessive or exaggerated 's' and 'sh' sounds. Also used to refer to a cymbal sound with too many high frequencies.


A repetition of a sound approximately 50 to 200 milliseconds after the original sound is heard.


When syncing two devices together, the controlling device becomes the master and the other device becomes the slave. The slave only responds to commands from the master; it does not also control the master. When syncing a sequencer to tape, the tape deck usually acts as the master and the sequencer becomes the slave.


A sound sample or track lacking detail and clarity. Also a track exhibiting poor transient response or excessive leakage between mics.


An acronym for Standard MIDI File, a file exchange format that allows different sequencer programs to share the same MIDI information.


Sounds which are not harsh and easy on the ears, due to a nearly flat frequency response, especially in the midrange response. Also used to describe sounds which have a lack of dips and peaks in the frequency response.


A timing standard (and an acronym) created by the Society of Motion Pictures and Television Engineers. This standard describes how hours, minutes, seconds, and frames are encoded (along with other miscellaneous data) into an audio signal that can be recorded to tape and read back.

SMPTE formats

SMPTE time code can be written in several ways, called formats. The formats differ depending on whether the time code is for film, European video, American video or music. Some common SMPTE formats are 24 frames per second, 25 frames per second, 30 frames per second or 30 drop frame.


A multi-pair or multi-channel microphone cable. Also, a multi-pair microphone cable hooked to a connector junction box.


When applied to a snare drum, the attack of the stick on the head, usually around 5 kHz. When describing a kick drum sound, the attack of the beater on the head of the kick drum. To emphasize the snap, you can boost the frequencies around 3 to 6 kHz and/or use a wooden beater.


Sounds or recorded tracks with poor transient response; too mellow or gentle. Sounds in which the peaks seem squashed or smeared.


A method of singing music that employs syllables (do,re,mi,fa,so,la,ti) to represent pitches, with a single syllable corresponding to a single note.


On an input module to a mixer, a switch allowing you to monitor the selected input signal by itself. All other inputs are muted so you may hear the input in isolation.

Song pointer message

The MIDI message that specifies, to a 16th note, how far into a piece you are. This permits a master device to send a song position pointer to a slave device, such as a drum machine, to begin playing at any point in the song

Song position pointer

A message sent by a master device that allows slaves to begin at any point within a sequence or song.


Longitudinal vibrations in a medium in the frequency range 20Hz to 20,000Hz.

Sound generator

A sample-playback module or synthesizer without a keyboard. The sounds are triggered by MIDI signals from an external keyboard, a dedicated hardware sequencer, or a computer sequencing program.

Sound pressure level

Abbreviated SPL, the acoustic pressure of a sound wave, measured in decibels above the threshold of hearing.

Spaced pair

A method of miking in which two microphones are spaced horizontally several feet apart. The mics are typically aimed straight ahead toward the sound source.


Conveying a sense of ambiance or room around the instruments. Sounds with noticeable reverberation and early reflections.


The consumer standard for digital audio transfers, using RCA-type plugs.


Also known as a 'Loudspeaker', a transducer that converts electrical energy (the signal) into acoustical energy (sound waves).


The output versus the frequency of a sound source, including the fundamental frequency and overtones.


An abbreviation for 'Sound pressure level', the acoustic pressure of a sound wave, measured in decibels above the threshold of hearing.


To join the ends of two pieces of magnetic tape with adhesive tape. Splice also refers to the taped joint between two sections of magnetic tape.


A circuit used to divide a signal into two or more identical signals to feed separate inputs. Split signals can then be processed or amplified in different ways.

Spot microphone

A microphone placed close to the sound source. Usually spot microphone signals are mixed with signals from more distant microphones to add presence.


Sound with a very limited dynamic range; highly compressed.

Stacking tracks

The technique of recording several performances of a musical part on separate tracks. so that the best portions of each performance can be played in sequence during mixdown.

Standard MIDI file

A universal MIDI file format, read by almost all MIDI software. Two formats are available--type 0, which is a single track sequence, and type 1, which is a multi-track sequence.

Standing wave

A stationary waveform, created by multiple reflections between opposite room surfaces. At certain points along the standing wave, the direct and reflected waves cancel, and at other points the waves add together or reinforce each other. In a room prone to standing waves, this resonance causes drastic changes in the perceived loudness of sounds at certain frequencies based on where you may be listening.


Sounds with an emphasized upper midrange response around 3 to 6 kHz. Also used to describe sound with a peaky, non-flat high-frequency response, or with too many overall high frequencies.

Step-time recording

Recording data into a sequencer one chord or note at a time, choosing the note durations for each chord or note. The sequence can then be played back at a normal tempo.


Originally an abbreviation for 'Stereophonic', an audio recording and reproduction system with correlated information between two discrete channels, meant to be heard over two or more loudspeakers to give the illusion of sound source localization and depth.

Stereo imaging

The ability of a stereo recording or monitor system to accurately position audio images at various locations between a stereo pair of speakers.

Stereo microphone

A microphone containing two coincident microphone capsules in a single housing for stereo recording.


A distorted track having unwanted harmonics, adding an edge or raspiness to the overall sound.

Sub dominant

A music theory term literally meaning the scale degree of four. May refer to a note or the chord based on a note.


A master volume control for an output buss.

Sub mediant

A music theory term literally meaning the scale degree of six. May refer to a note or the chord based on a note.


A smaller mix within a larger mix. Submixes are typically made for drums, keyboards, and/or effects.


A small mixer, which can be a separate mixer or contained within a larger mixer, that is used to feed submixed drums, keyboards, effects, etc. to an overall mix.

Supercardioid microphone

A unidirectional microphone that attenuates sounds arriving from the sides and rear, with maximum sound rejection occurring at 125 degrees either side off-axis.

Supply reel

Also known as the 'Feed reel', the reel on the left side of a tape recorder that unwinds during recording or playback.


The portion of the envelope of a sound in which the level is constant. It can also mean the ability of a sound to continue without decaying noticeably.


Delicate sounds exhibiting low distortion and a flat high-frequency response extended to the full range of human hearing (up to 20 kHz).


The addition of brass, strings, chorus, harp, orchestra, etc. to previously recorded rhythm tracks.


Short for 'synchronize' or 'synchronous recording'.

Sync box

1. A box that synchronizes a MIDI sequencer (either computer- or hardware- based) to a tape recorder, so the sequencer becomes a natural extension of the tape deck and does not waste audio tracks. The sync box permits the computer to shuttle forward and backward and stay precisely synched to what is on tape. 2. A unit that translates between the sync messages of MIDI and a special sync signal that is recorded on one tape track.

Sync stripe

A special audio signal recorded to one track on a tape that contains specially encoded digital information. This information can be decoded by a sync box and converted into meaningful MIDI sync information that is then sent to a sequencer.


The process of keeping two devices or software systems precisely locked together, typically through the use of SMPTE, MIDI time code, or MC/SPP standards. An example is keeping a sequencer precisely locked to a tape deck, maintaining the same location and speed.

Synchronous recording

The technique of using a record head as a playback head during an overdub session to keep the overdubbed parts in sync with the previously recorded music.


A musical instrument (usually with a keyboard) that generates sound electronically, and allows changes to the sound parameters to simulate conventional instruments or to create entirely new sounds.

Synthesizer programming

Creating new sounds, or changing existing sounds in a synthesizer.

System exclusive

Also known as 'Sys Ex', messages that represent unique or proprietary characteristics of devices or instruments.


A notation system for stringed instruments based on fingering numbers rather than standard musical symbols.

Tails out

A term describing a reel of tape wound with the end of the audio toward the outside of the reel. Tape stored in this manner is less likely to have audible print-through, since the tape must be rewound before playback. Any print-through that does happen to occur will sound after the original sound (instead of before), which is less problematic.


An intercom in the mixer for the producer and/or engineer and producer to talk from the control room and give feedback to the musicians in the studio room.


A recorded performance of a song, solo, or part. Many times, several takes are done of the same musical performance and the best one becomes the final product. At times, the best parts of several takes are brought together (digitally, or with tape splicing) to form a composite take.

Take sheet

A paper or computer notepad listing each take by number for each song, along with any notes on effects, performance, etc.

Take up reel

The reel on the right side of a reel-to-reel tape recorder that winds up the tape as is playing or recording.


Originally a short name for magnetic recording tape, a recording medium made of magnetic particles (usually ferric oxide) suspended in a binder and coated on a long strip of thin plastic, usually Mylar.

Tape editing

The splicing and rejoining of magnetic tape (not digital tape) to insert leader tape, to reorder recorded takes into a new sequence, or to delete entire musical passages.

Tape loop

An endless loop of tape made by splicing a length of tape end to end, used for continuous repetition of several seconds of audio.

Tape recorder

A device that converts an electrical audio signal into a magnetic audio signal on magnetic tape, and upon playback, converts the magnetic signal back to an electrical audio signal. Tape recorder parts include electronics, heads, and a transport to move the tape.


A tearsheet is an entire page from an actual print publication that has carried an advertisement, not just a clip of the ad. Tearsheets clearly show how the ad was produced in the publication, exactly how prominently it was placed on the page in relation to other ads and news, and whether or not competing ads were run on the same page.


A musical term meaning the range, from high to low, of a specific voice or instrument.


A sound or track where the fundamental frequencies are weak, relative to the harmonics. If the fundamental frequencies of an instrument are high, around 300 to 800 Hz for example, and the monitor system has a dip in the 400 Hz area, the instrument may sound thin, even though the monitor system is stronger in the lower range (below 200 Hz) of the frequency spectrum.

Three-pin connector

Also known as an XLR-connector, a professional audio connector for balanced audio signals. Pin 1 is connected to the cable shield, pin 2 connects to the signal hot lead and the third pin is connected to the signal return lead. Sometimes equipment is manufactured with pin 2 and 3 reversed, which causes problems when going from a balanced line to an unbalanced line.

3:1 rule

A microphone placement rule that recommends that when mixing multiple microphones to the same channel, the distance between microphones should be at least three times the distance from each microphone to the source of the sound. This prevents audible phase interference from changing the sound.


In a compressor or limiter, the input level above which compression or limiting takes place. Therefore the level of the audio must be above the threshold setting, or no effect is heard. In an expander or gate, the input level below which expansion or gating occurs.


A track or sound sample with audible low-pitched thumps, which can be caused by miking an acoustic guitar too closely, or by a guitar with excessive lows around 50 to 80 Hz.


A sound with an extremely deep bass, almost rumbling quality, with extended low-frequency response below 60 Hz.


A track or mix demonstrating good low-frequency transient response and detail. Tight is also used to describe the sound of a damped kick drum. It can also mean the absence of leakage between microphones.


The property of having tone color, or the distinctness of the sound of an instrument from any other.


The impression of a sound based upon its harmonic spectrum and envelope, i.e.. the distinctness of a sound that allows a person to differentiate it from other sounds. For example, when you hear a guitar, cymbal, or violin, each has a unique set of harmonics (therefore, tonal quality) that identifies it as a particular instrument.

Time code

A signal used to synchronize two or more tape transports, or a computer to a tape transport. As it applies to video, the signal describes the location on the tape in terms of hours, minutes, seconds and frames. Types of time code include SMPTE and MIDI.


A sound with a telephone-like tone having weak lows and a boosted mid-range, with a very narrow frequency range. The sound seems almost as if it is coming from the inside of a tin can.

Tonal balance

The balance or volume relationships between different regions of the frequency spectrum, including bass, lower midrange, midrange, upper midrange and highs.

Tone color

The sound or property of an instrument, as distinct from any other.


Refers to both high frequencies (i.e. "the top end") and the beginning of a song ("let's take it from the top").


Separate locations for recordings, usually containing a single channel of audio or MIDI data. Organizes recordings in a multi-track environment.


A device that converts energy from one form to another, such as a microphone or speaker.


An electronic component containing two magnetically coupled coils of wire. The input signal is transferred magnetically to the output, without a direct connection between input and output.


A relatively high amplitude, rapidly decaying, peak signal level. Untreated transients can cause audible distortion if levels are high enough.

Transient response

The ability of an audio component, such as a speaker or microphone, to accurately follow a transient.


A track or mix which is clear, detailed, not muddy, and which has a wide, flat frequency response. Also a mix exhibiting very low noise and distortion.


The mechanical system in a tape recorder that moves tape past the heads. The transport controls tape motion during recording, playback, fast forward and rewind.


A sound with weak lows and boosted mid-range, with a very narrow frequency range, as if it was heard on a telephone or from the inside of a metal trash can.


A control on a mixer for precise adjustment of level. Also, a control that adjusts the gain of a mic preamp to compensate for various signal levels of different strengths.


A sound having low-frequency resonances, almost as if the sound were coming from inside a bathtub.


A high frequency cone on a speaker.

Unbalanced line

An audio cable having one conductor surrounded by a shield that carries the return signal. The main disadvantage of an unbalanced line as compared to a balanced line is the potential for ground loops and hum, which balanced lines avoid.

Unidirectional microphone

A microphone that is most sensitive from sounds arriving in one (uni-) direction. Some examples of unidirectional mics include hypercardioid, supercardioid and cardioid


A continuously repeated musical phrase.


An acronym for Voltage-Controlled Oscillator. The VCO is the tone generator or sound source in an analog synth. The pitch that a VCO produces is a direct result of how much voltage it receives.


A track or sound sample with a slight amount of noise or and/or distortion, as if the speakers were covered with a silk veil. Veiled also describes a sound with slightly weak high frequencies. Opposite of transparent.


How loudly a note is struck.

Virtual tracking

When a MIDI sequencer is locked via a sync box to a tape deck, the sequencer tracks become virtual additions or extensions to those on tape, since it is not necessary to record the sequencer tracks to tape.


The careful equalization of a speaker/amplifier system (as in a recording studio monitor or sound reinforcement system) to achieve a particular sound or effect.

VU meter

A voltmeter with a specific transient response, calibrated in VUs (volume units). A VU meter is used to display the relative volume of various audio signals, and to set the optimum recording level.


A music track or mix with good bass, sufficient low frequencies and adequate fundamentals relative to harmonics. Opposite of thin. It can also mean pleasantly spacious with good reverberation at low frequencies. Some engineers will talk about a mix having warm highs, meaning sweet highs.


A short name for Wave Files, a Microsoft WindowsĂ… file format for digital audio data.


A graph of an audio signal's sound pressure or voltage over time. The waveform of a pure tone is a sine wave.


The physical length between corresponding points of successive cycles of a wave. Low frequencies have long wavelengths; high frequencies have short wavelengths.


A unit of magnetic flux.


Referring to a measurement made through a filter with a certain specific frequency response. An A-weighted measurement is taken through a filter that simulates the frequency response of the human ear.


A music track or sound with good low-frequency response below 50 Hz. It suggests an object of great mass or power, such as a jet or thunder.

White noise

A mixture of all frequencies between 18Hz and 22kHz at even amplitudes.


Also known as a pop filter, a screen placed between a microphone and a vocalist that attenuates or filters out pop or wind disturbances before they strike the microphone diaphragm. Usually windscreens are made of silk or open-cell plastic.


Practicing an instrument for the purpose of significant improvements in technique, style, or speed.


A low frequency loudspeaker.


A sound with weak high frequencies, almost sounding like a speaker with wool blanket over it. For drum tracks, an emphasis around 225 to 600 Hz contributes to a wooly sound.


An undesirable, slow periodic variation in tape speed.

XLR-type connector

The part number of an ITT Cannon device which has become the popular definition for a three-pin professional audio connector.

X-Y pair

Also known as coincident pair, a method of stereo recording using a stereo microphone, or two separate microphones, placed so that the microphone diaphragms occupy approximately the same point in space. Normally, the microphones are angled apart and mounted one directly above the other.


A cable that connects two cables in parallel in order to feed one signal to two separate inputs.

Dan McAvinchey is a guitarist and composer living in Raleigh, NC.

He believes every musician or composer has the power to write, record and release their own music.

Guitar Haus