GLOSSARY OF RECORDING TERMS
by Bruce Bartlett
A-B: A listening comparison between two audio programs, or
between two components playing the same program, performed by
switching immediately from one to the other. The levels of the
two signals are matched. See also Spaced-Pair.
AES: Audio Engineering Society.
AES/EBU: Also called IEC 988 Tape 1, an interface format for
digital signals, using a balanced 110 ohm mic cable terminated
with XLR-type connectors. See also S/PDIF.
A WEIGHTING: See Weighted.
ACCENT MICROPHONE: See Spot Microphone.
ACCESS JACKS: Two jacks in a console input module or output
module that allow access to points in the signal path, usually
for connecting a compressor. Plugging into the access jacks
breaks the signal flow and allows you to insert a signal
processor in series with the signal.
ACTIVE COMBINING NETWORK: A combining network with gain. See
Combining Network.
ALIGNMENT: The adjustment of tape-head azimuth and of
tape-recorder circuitry to achieve optimum performance from the
particular type of tape being used.
ALIGNMENT TAPE: A prerecorded tape with calibrated tones for
alignment of a tape recorder.
AMBIENCE: Room acoustics, early reflections and reverberation.
Also, the audible sense of a room or environment surrounding a
recorded instrument.
AMBIENCE MICROPHONE: A microphone placed relatively far from its
sound source to pick up ambience.
AMPLITUDE, PEAK: On a graph of a sound wave, the sound pressure
of the waveform peak. On a graph of an electrical signal, the
voltage of the waveform peak. The amplitude of a sound wave or
signal as measured on a meter is 0.707 times the peak amplitude.
ANALOG-TO-DIGITAL (A/D) CONVERTER: A circuit that converts an
analog audio signal into a stream of digital data (bit stream).
ASSIGN: To route or send an audio signal to one or more selected
channels.
ATRAC: Adaptive Transform Acoustic Coding. A data compression
scheme that reduces by 5:1 the storage needed for digital audio.
ATRAC is a perceptual coding method, which omits data deemed
inaudible due to masking.
ATTACK: The beginning of a note. The first portion of a note's
envelope in which a note rises from silence to its maximum volume.
ATTACK TIME: In a compressor, the time it takes for gain
reduction to occur in response to a musical attack.
ATTENUATE: To reduce the level of a signal.
ATTENUATOR: In a mixer (or mixing console) input module, an
adjustable resistive network that reduces the microphone signal
level to prevent overloading of the input transformer and mic
preamplifier.
AUTOLOCATE: A recorder function which makes the tape or disk go
to a program address (counter time) at the press of a button.
AUTOMATED MIXING: A system of mixing in which a computer
remembers and updates console settings. With this system, a mix
can be performed and refined in several stages and played back at
a later date exactly as set u previously.
AUXILIARY BUS (AUX-BUS): See Effects Bus.
AUXILIARY SEND (AUX-SEND): See Effects Send.
A/V DRIVE: A hard disk drive meant for audio/video use. It
postpones thermal recalibration until the disk is inactive,
preventing data errors.
AZIMUTH: In a tape recorder, the angular relationship between the
head gap and the tape path.
AZIMUTH ALIGNMENT: The mechanical adjustment of the record or
playback head to bring it into proper alignment (90 degrees) with
the tape path.
BACK-TIMING: A technique of cueing up the musical background or a
sound effect to a narration track so that the music or effect
ends simultanously with the narration.
BAFFLED-OMNI: A stereo miking arrangment that uses two ear-spaced
omnidirectional microphones separated by a hard padded baffle.
BALANCE: The relative volume levels of various tracks or
instruments.
BALANCED AC POWER: AC power from a center-tapped power
transformer. Instead of one 120V line and one 0V line, it has two
60V lines. They are in phase with each other, and sum to 120V.
But they are connected to the center-tap ground out of phase (one
is +60V; the other is -60V). Any hum and noise on the grounding
system cancels out.
BALANCED LINE: A cable with two conductors surrounded by a
shield, in which each conductor is at equal impedance to ground.
With respect to ground, the conductors are at equal potential but
opposite polarity; the signal flows through both conductors.
BANDPASS FILTER: In a crossover, 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,
guitar, drums, and sometimes keyboard).
BASS TRAP: An assembly that absorbs low-frequency sound waves in
the studio.
BIAMPLIFICATION (BIAMPING): Driving a woofer and tweeter with
separate power amplfiers. An active crossover is connected ahead
of these power amplifiers.
BIAS: In tape-recorder electronics, an ultrasonic signal that
drives the erase head. This signal is also mixed with the audio
signal applied to the record head to reduce distortion.
BIDIRECTIONAL MICROPHONE: A microphone that is most sensitive to
sounds arriving from two directions--in front of and behind the
microphone. It rejects sounds approaching either side of the
microphone. Sometimes called a cosine or figure-eight microphone
because of the shape of its polar pattern.
BINAURAL RECORDING: A 2-channel recording made with an
omnidirectional microphone mounted near each ear of a human or a
dummy head, for playback over headphones. The object is to
duplicate the acoustic signal appearing at each ear.
BLUMLEIN ARRAY: A stereo microphone technique in which two
coincident bidirectional microphones are angled 90 degrees apart
(45 degrees to the left and right of center).
BOARD: See Mixing Console.
BOUNCING TRACKS: A process in which two or more tracks are mixed,
and the mixed tracks are recorded on an unused track or tracks.
Then the original tracks can be erased, which frees them up for
recording more instruments.
BOUNDARY MICROPHONE: A microphone designed to be used on a
boundary (a hard reflective surface). The microphone capsule is
mounted very close to the boundary so that direct and reflected
sounds arrive at the microphone diaphragm in phase (or nearly so)
for all frequencies in the audible band.
BREATHING: The unwanted audible rise and fall of background noise
that may occur with a compressor. Also called pumping.
BULK TAPE ERASER: A large electromagnet used to erase a whole
reel of recording tape at once.
BUS: A common connection of many different signals. An output of
a mixer or submixer. A channel that feeds a tape track, signal
processor, or power amplifier.
BUS IN: An input to a program bus, usually used for effects
returns.
BUS MASTER: In the output section of a mixing console, a
potentiometer (fader or volume control) that controls the output
level of a bus.
BUS OUT: The output connector of a bus.
BUS TRIM: A control in the output section of a mixing console
that provides variable gain control of a bus, used in addition to
the bus master for fine adjustment.
BUS MASTER: In the output section of a mixing console, a
potentiometer (fader or volume control) that controls the output
level of a bus.
BUZZ: An unwanted edgy tone that sometimes accompanies audio,
containing high harmonics of 60 Hz.
CALIBRATION: See Alignment.
CAPACITOR: An electronic component that stores an electric
charge. It is formed of two conductive plates separated by an
insulator called a dielectric. A capacitor passes AC but blocks
DC.
CAPACITOR MICROPHONE: See Condenser Microphone.
CAPSTAN: 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.
CARDIOID MICROPHONE: A unidirectional microphone with side
attenuation of 6 dB and maximum rejection of sound at the rear of
the microphone (180 degrees off-axis). A microphone with a
heart-shaped directional pattern.
CD-R: CD-Recordable, a recordable compact disc that cannot be
rewritten. Once recorded, it cannot be erased and reused.
CD-RW: CD-Rewritable, a recordable compact disc that can be
rewritten. Once recorded it can be erased and reused.
CHANNEL: A single path of an audio signal. Usually, each channel
contains a different signal.
CHANNEL ASSIGN: See Assign.
CHORUS: 1. A special effect in which a signal is delayed by 15 to
35 milliseconds, the delayed signal is combined with the original
signal, and the delay is varied randomly or periodically. This
creates a wavy, shimmering effect. 2. The main portion of a song
that is repeated several times throughout the song with the same
lyrics.
CLEAN: Free of noise, distortion, overhang, leakage. Not muddy.
CLEAR: Easy to hear, easy to differentiate. Reproduced with
sufficient high frequencies.
COINCIDENT-PAIR: A stereo microphone, or two separate
microphones, placed so that the microphone diaphragms occupy
approximately the same point in space. They are angled apart and
mounted one directly above the other.
COMB-FILTER EFFECT: The frequency response caused by combining a
sound with its delayed replica. The frequency response has a
series of peaks and dips caused by phase interference. The peaks
and dips resemble the teeth of a comb.
COMBINING AMPLIFIER: An amplifier at which the outputs of two or
more signal paths are mixed together to feed a single track of a
tape recorder.
COMBINING NETWORK: A resistive network at which the outputs of
two or more signal paths are mixed together to feed a single
track of a tape recorder.
COMPLEX WAVE: A wave with more than one frequency component.
COMPING: Recording composite tracks.
COMPOSITE TRACKS: The process of recording several performances
of a musical part on different tracks, so that the best segments
of each performance can be played in sequence during mixdown.
COMPRESSION: 1. The portion of a sound wave in which molecules
are pushed together, forming a region with higher-than-normal
atmospheric pressure. 2. In signal processing, the reduction in
dynamic range or gain caused by a compressor. 3. In computing,
data compression reduces the number of bytes in a file without
losing essential information.
COMPRESSION RATIO (SLOPE): In a compressor, the ratio of the
change in input level (in dB) to the change in output level (in
dB). For example, a 2:1 ratio means that for every 2 dB change in
input level, the output level changes 1 dB.
COMPRESSOR: A signal processor that reduces dynamic range or gain
by means of automatic volume control. An amplifier whose gain
decreases as the input signal level increases above a preset
point.
CONDENSER MICROPHONE: A microphone that works on the principle of
variable capacitance to generate an electrical signal. The
microphone diaphragm and an adjacent metallic disk (called a
backplate) are charged to form two plates of a capacitor.
Incoming sound waves vibrate the diaphragm, varying its spacing
to the backplate, which varies the capacitance, which in turn
varies the voltage between the diaphragm and backplate.
CONNECTOR: A device that makes electrical contact between a
signal-carrying cable and an electronic device, or between two
cables. A device used to connect or hold together a cable and an
electronic component so that a signal can flow from one to the
other.
CONSOLE: See Mixing Console.
CONTACT PICKUP: A transducer that contacts a musical instrument
and converts its mechanical vibrations into a corresponding
electrical signal.
CONTROL ROOM: The room in which the engineer controls and
monitors the recording. It houses most of the recording hardware.
CROSSOVER: An electronic network that divides an incoming signal
into two or more frequency bands.
CROSSOVER, ACTIVE (ELECTRONIC CROSSOVER): A crossover with
amplifying components, used ahead of the power amplifiers in a
biamped or triamped speaker system.
CROSSOVER FREQUENCY: The single frequency at which both filters
of a crossover network are down 3 dB.
CROSSOVER, PASSIVE: A crossover with passive (nonamplifying)
components, used after the power amplifier.
CROSSTALK: The unwanted transfer of a signal from one channel to
another. Crosstalk often occurs between adjacent tracks within a
record or playback head in a tape recorder, or between input
modules in a console.
CUE, CUE SEND: In a mixing-console input module, a control that
adjusts the level of the signal feeding the cue mixer that feeds
a signal to headphones in the studio.
CUE LIST: See Edit Decision List.
CUE MIXER: A submixer in a mixing console that takes signals from
cue sends as inputs and mixes them into a composite signal that
drives headphones in the studio.
CUE SHEET: Used during mixdown, a chronological list of
mixing-console control adjustments required at various points in
the recorded song. These points may be indicated by tape-counter
or ABS-time readings.
CUE SYSTEM: A monitor system that allows musicians to hear
themselves and previously recorded tracks through headphones.
DAMPING FACTOR: The ability of a power amplifier to control or
damp loudspeaker vibrations. The lower the amplifier's output
impedance, the higher the damping factor.
DAT (R-DAT): A digital audio tape recorder that uses a rotating
head to record digital audio on tape.
DATA COMPRESSION: A scheme for reducing the amount of data
storage on a medium. See ATRAC.
DAW: Abbreviation for digital audio workstation.
dB: Abbreviation for decibel.
DEAD: Having very little or no reverberation.
DECAY: The portion of the envelope of a note in which the
envelope goes from maximum to some midrange level. Also, the
decline in level of reverberation over time.
DECAY TIME: See Reverberation time.
DECIBEL: 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.
dBV is decibels relative to 1 volt.
dBu is decibels relative to 0.775 volt.
dBm is decibels relative to 1 milliwatt.
dBA is decibels, A weighted (see Weighted)
DECODED TAPE: A tape that is expanded after being compressed by a
noise-reduction system. Such a tape has normal dynamic range.
DE-ESSER: A signal processor that removes excessive sibilance
("s" and "sh" sounds) by compressing high frequencies around 5 to
10 kHz.
DELAY: The time interval between a signal and its repetition. A
digital delay or a delay line is a signal processor that delays a
signal for a short time.
DEMAGNETIZER (DEGAUSSER): An electromagnet with a probe tip that
is touched to elements of the tape path (such as tape heads and
tape guides) to remove residual magnetism.
DEPTH: The audible sense of nearness and farness of various
instruments. Instruments recorded with a high ratio of
direct-to-reverberant sound are perceived as being close;
instruments recorded with a low ratio of direct-to-reverberant
sound are perceived as being distant.
DESIGN CENTER: The portion of fader travel (usually shaded),
about 10 to 15 dB from the top, in which console gain is
distributed for optimum headroom and signal-to-noise ratio.
During normal operation, each fader in use should be placed at or
near design center.
DESIGNATION STRIP: A strip of paper taped near console faders to
designate the instrument that each fader controls.
DESK: The British term for mixing console.
DESTRUCTIVE EDITING: In a digital audio workstation, editing that
rewrites the data on disk. A destructive edit cannot be undone.
DI: Short for direct injection, recording with a direct box.
DIFFUSION: An even distribution of sound in a room.
DIGITAL AUDIO: An encoding of an analog audio signal in the form
of binary digits (ones and zeros).
DIGITAL AUDIO WORKSTATION (DAW): A computer, sound card, and
editing software that allows you to record, edit and mix audio
programs entirely in digital form. Stand-alone DAWs include real
mixer controls; computer DAWS have virtual controls on-screen.
DIGITAL RECORDING: A recording system in which the audio signal
is stored in the form of binary digits.
DIGITAL-TO-ANALOG CONVERTER: A circuit that converts a digital
audio signal into an analog audio signal.
DIM: To reduce the monitor volume temporarily by a preset amount
so that you can carry on a conversation.
DIRECT BOX: A device used for connecting an amplified instrument
directly to a mixer mic input. The direct box converts a
high-impedance unbalanced audio signal into a low-impedance
balanced audio signal.
DIRECT INJECTION (DI): Recording with a direct box.
DIRECTIONAL MICROPHONE: A microphone that has different
sensitivity in different directions. A unidirectional or
bidirectional microphone.
DIRECT OUTPUT, DIRECT OUT: An output connector following a mic
preamplifier, fader and equalizer, used to feed the signal of one
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 reflections.
DISTORTION: An unwanted change in the audio waveform, causing a
raspy or gritty sound quality. The appearance of frequencies in a
device's output signal that were not in the input signal.
Distortion is caused by recording at too high a level, improper
mixer settings, components failing, or vacuum tubes distorting.
(Distortion can be desirable--for an electric guitar, for
example.)
DOLBY TONE: A reference tone recorded at the beginning of a
Dolby-encoded tape for alignment purposes.
DOUBLING: A special effect in which a signal is combined with its
15 to 35 millisecond delayed replica. This process mimics the
sound of two identical voices or instruments playing in unison.
In another type of doubling, two indentical performances are
recorded and played back to thicken the sound.
DROP-FRAME: For color video production, a mode of SMPTE time code
that causes the time code to match the clock on the wall. Once
every minute, frame numbers 00 and 01 are dropped, except every
10th minute.
DROP-OUT: During playback of a tape recording, a momentary loss
of signal caused by separation of the tape from the playback head
by dust, tape-oxide irregularity, etc.
DRUM MACHINE: A device that plays samples of real drums, and
includes a sequencer to record rhythm patterns.
DRY: Having no echo or reverberation. Referring to a close-
sounding signal that is not yet processed by a reverberation or
delay device.
DSP: Abbreviation for Digital Signal Processing, modifying a
signal in digital form.
DVD: Digital Versatile Disc. A storage medium the size of a
compact disc which holds much more data. The DVD stores video,
audio, or computer data.
DYNAMIC MICROPHONE: A microphone that generates electricity when
sound waves cause a conductor to vibrate in a stationary magnetic
field. The two types of dynamic microphone are moving coil and
ribbon. A moving-coil microphone is usually called a dynamic
microphone.
DYNAMIC RANGE: The range of volume levels in a program from
softest to loudest.
EARTH GROUND: A connection to moist dirt (the ground we walk on).
This connection is usually done via a long copper rod or an
all-metal cold-water pipe.
ECHO: A delayed repetition of a signal or sound. A sound delayed
50 milliseconds or more, combined with the original sound.
ECHO CHAMBER: A hard-surfaced room containing a widely separated
loudspeaker and microphone, once used for creating reverberation.
EDIT DECISION LIST (EDL): A list of program events in order, plus
their starting and ending times.
EDITING: The cutting and rejoining of magnetic tape to delete
unwanted material, to insert leader tape, or to rearrange
recorded material into the desired sequence. Also, the same
actions performed with a digital audio workstation, hard-disk
recorder, or MiniDisc recorder-mixer--without cutting any tape.
EDITING BLOCK: A metal block that holds magnetic tape during the
editing/splicing procedure.
EFFECTS: Interesting sound phenomena created by signal
processors, such as reverberation, echo, flanging, doubling,
compression, or chorus.
EFFECTS BUS: The bus that feeds effects devices (signal
processors).
EFFECTS LOOP: A set of connectors in a mixer for connecting an
external effects unit, such as a reverb or delay device. The
effects loop includes a send section and a receive section. See
Effects Send, Effects Return.
EFFECTS MIXER: A submixer in a mixing console that combines
signals from effects sends, and then feeds the mixed signal to
the input of a special-effects device, such as a reverberation
unit.
EFFECTS RETURN (EFFECTS RECEIVE): In the output section of a
mixing console, a control that adjusts the amount of signal
received from an effects unit. Also, the connectors in a mixer to
which you connect the effects-unit output signal. They might be
labeled "bus in" instead. The effects-return signal is mixed with
the program bus signal.
EFFECTS SEND: In an input module of a mixing console, a control
that adjusts the amount of signal sent to a special-effects
device, such as a reverberation or delay unit. Also, the
connector in a mixer which you connect to the input of an effects
unit. The effects-send control normally adjusts the amount of
reverberation or echo heard on each instrument.
EFFICIENCY: In a loudspeaker, the ratio of acoustic power output
to electrical power input.
EIA: Electrical Industries Association.
EIA RATING: A microphone-sensitivity specification that states
the microphone output level in dBm into a matched load for a
given Sound Pressure Level (SPL). SPL + dB (EIA rating) = dBm
output into a matched load.
ELECTRET-CONDENSER MICROPHONE: A condenser microphone in which
the electrostatic field of the capacitor is generated by an
electret--a material that permanently stores an electrostatic
charge.
ELECTROSTATIC FIELD: The force field between two conductors
charged with static electricity.
ELECTROSTATIC INTERFERENCE: The unwanted presence of an
electrostatic hum field in signal conductors.
ENCODED TAPE: A tape containing a signal compressed by a
noise-reduction unit.
END-ADDRESSED: Referring to a microphone whose main axis of
pickup is perpendicular to the front of the microphone. You aim
the front of the mic at the sound source. See Side-Addressed.
ENVELOPE: The rise and fall in volume of one note. The envelope
connects successive peaks of the waves comprising a note. Each
harmonic in the note might have a different envelope.
EQUALIZATION (EQ): The adjustment of frequency response to alter
the tonal balance or to attenuate unwanted frequencies.
EQUALIZER: A circuit (usually in each input module of a mixing
console, or in a separate unit) that alters the frequency
spectrum of a signal passed through it.
ERASE: To remove an audio signal from magnetic tape by applying
an ultrasonic varying magnetic field so as to randomize the
magnetization of the magnetic particles on the tape.
ERASE HEAD: A head in a tape recorder that erases the signal on
tape.
EXPANDER: 1. A signal processor that increases the dynamic range
of a signal passed through it. 2. An amplifer whose gain
decreases as its input level decreases. When used as a noise
gate, an expander reduces the gain of low-level signals to reduce
noise between notes.
FADE-OUT: To gradually reduce the volume of the last several
seconds of a recorded song, from full level down to silence, by
slowly pulling down the master fader.
FADER: A linear or sliding potentiometer (volume control), used
to adjust signal level.
FEED: 1. To send an audio signal to some device or system. 2. An
output signal sent to some device or system.
FEEDBACK: 1. The return of some portion of an output signal to
the system's input. 2. The squealing sound you hear when a PA
system microphone picks up its own amplified signal through a
loudspeaker.
FEED REEL: The left-side reel on a tape recorder that unwinds
during recording or playback.
FILTER: 1. A circuit that sharply attenuates frequencies above or
below a certain frequency. Used to reduce noise and leakage above
or below the frequency range of an instrument or voice. 2. A MIDI
Filter removes selected note parameters.
FLANGING: A special effect in which a signal is combined with its
delayed replica, and the delay is varied between 0 and 20
milliseconds. A hollow, swishing, ethereal effect like a
variable-length pipe, or like a jet plane passing overhead. A
variable comb filter produces the flanging effect.
FLETCHER MUNSON EFFECT: Named after the two people who discovered
it, the psychoacoustical phenomenon in which the subjective
frequency response of the ear changes with program level. Due to
this effect, a program played at a lower volume than the original
level subjectively loses low- and high-frequency response.
FLOAT: To disconnect from ground.
FLUTTER: A rapid periodic variation in tape speed.
FLUTTER ECHOES: A rapid series of echoes that occurs between two
parallel walls.
FLUX: Magnetic lines of force.
FLUXIVITY: The measure of the flux density of a magnetic
recording tape, per unit of track width.
FLY-IN (LAY-IN)--To copy part of a recorded track onto another
recorder, then re-record that copy back onto the original
multitrack tape in a different part of the song, in sync with
other recorded tracks. For example, copy the vocal track from the
first chorus of the song onto an external recorder or sampler.
Rerecord (fly-in) that copy onto the multitrack tape at the
second chorus. Then the first and second choruses have identical
vocal performances.
FOLDBACK (FB): See Cue System.
FREQUENCY: The number of cycles per second of a sound wave or an
audio signal, measured in hertz (Hz). A low frequency (for
example, 100 Hz) has a low pitch; a high frequency (for example,
10,000 Hz) has a high pitch.
FREQUENCY RESPONSE: 1. The range of frequencies that an audio
device will reproduce at an equal level (within a tolerance, such
as +/- 3 dB). 2. The range of frequencies that a device (mic,
human ear, etc.) can detect.
FULL TRACK: A single tape track recorded across the full width of
a tape.
FUNDAMENTAL: The lowest frequency in a complex wave.
GAIN: Amplification. The ratio, expressed in decibels, between
the output voltage and the input voltage, or between the output
power and the input power.
GAP: In a tape-recorder head, the thin break in the electromagnet
that contacts the tape.
GATE: 1. To turn off a signal when its amplitude falls below a
pre-set value. 2. The signal-processing device used for this
purpose. See also Noise Gate.
GATED REVERB: Reverberation with the reverberant "tail" cut off
before it fades out.
GENERATION: A copy of a tape or a bounce of a track. A copy of
the original master recording is a first generation tape. A copy
made from the first generation tape is a second generation, and
so on.
GENERATION LOSS: The degradation of signal quality (the increase
in noise and distortion) that occurs with each successive
generation of a tape recording.
GOBO: A moveable partition used to prevent the sound of an
instrument from reaching another instrument's microphone. Short
for go-between.
GRAPHIC EQUALIZER: An equalizer with a horizontal row of faders;
the fader-knob positions indicate graphically the frequency
response of the equalizer. Usually used to equalize monitor
speakers for the room they are in. Sometimes used for complex EQ
of a track.
GROUND: The zero-signal reference point for a system of audio
components.
GROUND BUS: A common connection to which equipment is grounded,
ususally a heavy copper plate.
GROUNDING: Connecting pieces of electronic equipment to ground.
Proper grounding ensures that there is no voltage difference
between equipment chassis. An electrostatic shield needs to be
grounded to be effective.
GROUND LOOP: 1. A loop or circuit formed of ground leads. 2. The
loop formed when unbalanced components are connected together via
two ground paths--the connecting-cable shield and the power
ground. Ground loops cause hum and should be avoided.
GROUP: See Submix.
GUARD BAND: The spacing between tracks on a multitrack tape or
tape head, used to prevent crosstalk.
HALF-TRACK: A tape track recorded across approximately half the
width of a tape. A half-track recorder usually records two such
tracks simultaneously in the same direction to make a stereo
recording.
HARD DISK: A random-access storage medium for computer data. A
hard disk drive contains a stack of magnetically coated hard
disks that are read by, and written to by, an electromagnetic
head.
HARD DISK RECORDER: A device dedicated to recording digital audio
on a hard disk drive. A hard disk recorder-mixer includes a
built-in mixer.
HARMONIC: An overtone whose frequency is a whole-number multiple
of the fundamental frequency.
HARMONIZER: A signal processor that provides a wide variety of
pitch-shifting and delay effects.
HEAD: An electromagnet in a tape recorder that either erases the
audio signal on tape, records a signal on tape, or plays back a
signal that is already on tape.
HEAD GAP: See Gap.
HEADPHONES: A head-worn transducer that covers the ears and
converts electrical audio signals into sound waves.
HEADROOM: The safety margin, measured in decibels, between the
signal level and the maximum undistorted signal level. In a tape
recorder, the dB difference between standard operating level
(corresponding to a 0 VU reading) and the level causing 3 percent
total harmonic distortion. High-frequency headroom increases with
analog tape speed.
HERTZ (Hz): Cycles per second, the unit of measurement of
frequency.
HIGHPASS FILTER: A filter that passes frequencies above a certain
frequency and attenuates frequencies below that same frequency. A
low-cut filter.
HISS: A noise signal containing all frequencies, but with greater
energy at higher octaves. Hiss sounds like wind blowing through
trees. It is usually caused by random signals generated by
microphones, electronics, and magnetic tape.
HOT: 1. A high recording level causing slight distortion, maybe
used for special effect. 2. A condition in which a chassis or
circuit has a potentially dangerous voltage on it. 3. Referring
to the conductor in a microphone cable which has a positive
voltage on it at the instant that sound pressure moves the
diaphragm inward.
HUM: An unwanted low-pitched tone (60 Hz and its harmonics) heard
in the monitors. The sound of interference generated in audio
circuits and cables by AC power wiring. Hum pickup is caused by
such things as faulty grounding, poor shielding, and ground loops.
HYPERCARDIOID MICROPHONE: A directional microphone with a polar
pattern that has 12 dB attenuation at the sides, 6 dB attenuation
at the rear, and two nulls of maximum rejection at 110 degrees
off axis.
IMAGE: An illusory sound source located somewhere around the
listener. An image is generated by two or more loudspeakers. In a
typical stereo system, images are located between the two stereo
speakers.
IMPEDANCE: The opposition of a circuit to the flow of alternating
current. Impedance is the complex sum of resistance and
reactance. Abbreviated as Z.
INPUT: The connection going into an audio device. In a mixer or
mixing console, a connector for a microphone, line-level device,
or other signal source.
INPUT ATTENUATOR: See Attenuator.
INPUT MODULE: In a mixing console, the set of controls affecting
a single input signal. An input module usually include an
attenuator (trim), fader, equalizer, effects send, cue send, and
channel-assign controls.
INPUT SECTION: The row of input modules in a mixing console.
INPUT/OUTPUT (I/O) CONSOLE (IN-LINE CONSOLE): A mixing console
arranged so that input and output sections are aligned
vertically. Each module (other than the monitor section) contains
one input channel and one output channel.
INSERT JACKS: See Access jacks.
JACK: A female or receptacle-type connector for audio signals
into which a plug is inserted.
KEYBOARD WORKSTATION: Several MIDI components in one chassis--a
keyboard, a sample player, a sequencer, and perhaps a synthesizer
and disk drive.
KILO: A prefix meaning one thousand. Abbreviated k.
LAY-IN: See Fly-In.
LEADERING: The process of splicing leader tape between program
selections.
LEADER TAPE: Plastic or paper tape without an oxide coating, used
for a spacer between takes (for silence between songs).
LEAKAGE: The overlap of an instrument's sound into another
instrument's microphone. Also called bleed or spill.
LEDE: Abbreviation for Live-End/Dead-End, a type of control room
acoustic treatment in which the front half of the control room
prevents early reflections to the mixing position, while the back
half of the control room reflects diffused sound to the mixing
position.
LED INDICATOR: A recording-level indicator using one or more
Light Emitting Diodes.
LEVEL: The degree of intensity of an audio signal--the voltage,
power, or sound pressure level. The original definition of level
is the power in watts.
LEVEL SETTING: In a recording system, the process of adjusting
the input-signal level to obtain maximum level on the recording
media without distortion. A VU meter or other indicator shows
recording level.
LIMITER: A signal processor whose output is constant above a
preset input level. A compressor with a compression ratio of 10:1
or greater, with the threshold set just below the point of
distortion of the following device. Used to prevent distortion of
attack transients or peaks.
LINE LEVEL: In balanced professional recording equipment, a
signal whose level is approximately 1.23 volts (+4 dBm). In
unbalanced equipment (most home hi-fi or semipro recording
equipment), a signal whose level is approximately 0.316 volt (-10
dBV).
LIVE: 1. Having audible reverberation. 2. Occuring in real-time,
in person.
LIVE RECORDING: A recording made at a concert. Also, a recording
made of a musical ensemble playing all at once, rather than
overdubbing.
LOCALIZATION: The ability of the human hearing system to tell the
direction of a real or illusionary sound source.
LOOP: In a sampling program, to play the sustain portion of a
sound's envelope repeatedly.
LOUDSPEAKER: A transducer that converts electrical energy (the
signal) into acoustical energy (sound waves).
LOWPASS FILTER: A filter that passes frequencies below a certain
frequency and attenuates frequencies above that same frequency. A
high-cut filter.
M: Abbreviation for mega, or one million (as in megabytes).
MAGNETIC RECORDING TAPE: A recording medium made of magnetic
particles (usually ferric oxide) suspended in a binder and coated
on long strip of thin plastic (usally Mylar).
MASK: To hide or cover up one sound with another sound. To make a
sound inaudible by playing another sound along with it.
MASTER FADER: A volume control that affects the level of all
program buses simultaneously. It is the last stage of gain
adjustment before the 2-track recorder.
MASTER TAPE: A completed tape used to generate tape copies or
compact discs.
MD: Abbreviation for MiniDisc.
MDM: Abbreviation for Modular Digital Multitrack.
MEMORY: A group of integrated circuit chips used to store
digital data temporarily or permanently (such as an audio signal
in digital format).
MEMORY REWIND: A tape-recorder function that rewinds the tape to
a preset tape-counter position.
METER: A device that indicates voltage, resistance, current, or
signal level.
MIC: An abbreviation for microphone.
MIC LEVEL: The level or voltage of a signal produced by a
microphone, typically 2 millivolts.
MIC PREAMP: See Preamplifier.
MICROPHONE: A transducer or device that converts an acoustical
signal (sound) into a corresponding electrical signal.
MICROPHONE TECHNIQUES: The selection and placement of microphones
to pick up sound sources.
GLOSSARY OF RECORDING TERMS
Part 2 of 3
by Bruce Bartlett
MIDI: Abbreviation for Musical Instrument Digital Interface, a
specification for a connection between synthesizers, drum
machines, and computers that allows them to communicate with
and/or control each other.
MIDI CHANNEL: A route for transmitting and receiving MIDI
signals. Each channel controls a separate MIDI musical instrument
or synth patch. Up to 16 channels can be sent on a single MIDI
cable.
MIDI CONTROLLER: A musical performance device (keyboard, drum
pads, breath controller, etc.) that outputs a MIDI signal
designating note numbers, note on, note off, and so on.
MIDI IN: A connector in a MIDI device that receives MIDI
messages.
MIDI INTERFACE: A circuit that plugs into a computer, and
converts MIDI data into computer data for storage in memory or on
hard disk. The interface also converts computer data into MIDI
data.
MIDI OUT--A connector in a MIDI device that transmits MIDI
messages.
MIDI THRU--A connector in a MIDI device that duplicates the MIDI
information at the MIDI-In connector. Used to connect another
MIDI device in the series.
MID-SIDE: A coincident-pair stereo microphone technique using a
forward-facing unidirectional, omnidirectional, or bidirectional
mic and a side-facing bidirectional mic. The microphone signals
are summed and differenced to produce right- and left-channel
signals.
MILLI: A prefix meaning one thousandth, abbreviated m.
MIKE: To pick up with a microphone.
MINIDISC (MD): A rewritable, magneto-optical storage medium that
is read by a laser. It resembles a compact disc in a 2.5-inch
square housing. MD recorders use a data compression scheme called
ATRAC.
MIX: 1. To combine two or more different signals into a common
signal. 2. A control on a delay unit that varies the ratio
between the dry signal and the delayed signal.
MIXDOWN: The process of playing recorded tape tracks through a
mixing console and mixing them to two stereo channels for
recording on a two-track tape recorder.
MIXER: A device that mixes or combines audio signals and controls
the relative levels of the signals.
MIXING CONSOLE: A large mixer with additional functions such as
equalization or tone control, pan pots, monitoring controls, solo
functions, channel assigns, and control of signals sent to
external signal processors.
MODULAR DIGITAL MULTITRACK (MDM): A multitrack tape recorder that
records 8 tracks digitally on a videocassette. Several 8-track
modules can be connected together to add more tracks in sync. Two
examples of MDMs are the Alesis ADAT-XT and TASCAM DA-38.
MONITOR: A loudspeaker in a control room, or headphones, used for
judging sound quality. Also, a video display screen used with a
computer.
MONITORING: Listening to an audio signal with a monitor.
MONAURAL: Referring to listening with one ear. Often incorrectly
used to mean monophonic.
MONO, MONOPHONIC: 1. Referring to a single channel of audio. A
monophonic program can be played over one or more loudspeakers,
or one or more headphones. 2. Describing a synthesizer that plays
only one note at a time (not chords).
MONO-COMPATIBLE: A characteristic of a stereo program, in which
the program channels can be combined to a mono program without
altering the frequency response or balance. A mono-compatible
stereo program has the same frequency response in stereo or mono
because there is no delay or phase shift between channels to
cause phase interference.
MOVING-COIL MICROPHONE: A 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 struck with
sound waves. Usually called a dynamic microphone.
MP3: MPEG-1 Layer 3, a format for data-compressing an audio file
to 1/12 its original size or smaller. Compression at 128 kbps
and 44.1K sampling rate is said to be CD quality. Because of
their relatively small size, MP3 files can be distributed on the
Internet with fairly short upload and download times.
M-S RECORDING: See Mid-side.
MUDDY: Unclear sounding; having excessive leakage, reverberation,
or overhang.
MULTIEFFECTS PROCESSOR: See Multiprocessor.
MULTIPLE-D MICROPHONE: A directional microphone which has
multiple sound-path lengths between its front and rear sound
entries. This type of microphone has minimal proximity effect.
MULTIPROCESSOR: A signal processor that can perform several
different signal-processing functions.
MULTITIMBRAL--In a synthesizer, the ability to produce two or
more different patches or timbres at the same time.
MULTITRACK: Referring to a recorder or tape-recorder head that
has more than two tracks.
MUTE: To turn off an input signal on a mixing console by
disconnecting the input-module output from channel assign and
direct out. During mixdown, the mute function is used to reduce
tape noise during silent portions of tracks, or to turn off
unused performances. During recording, mute is used to turn off
mic signals.
NEAR COINCIDENT: A stereo microphone technique in which two
directional microphones are angled apart symmetrically on either
side of center and spaced a few inches apart horizontally.
NEAR-FIELD MONITORING: A monitor-speaker arrangement in which the
speakers are placed very near the listener (usually just behind
the mixing console) to reduce the audibility of control-room
acoustics.
NOISE: Unwanted sound, such as hiss from electronics or tape. An
audio signal with an irregular, non-periodic waveform.
NOISE GATE: A gate used to reduce or eliminate noise between
notes.
NOISE-REDUCTION SYSTEM: A signal processor (Dolby or dbx) used to
reduce tape hiss (and sometimes print-through) caused by the
recording process. Some of these systems compress the signal
during recording and expand it in a complementary fashion during
playback.
NON-DESTRUCTIVE EDITING: In a digital audio workstation, editing
done by changing pointers (location markers) to information on
the hard disk. A non-destructive edit can be undone.
NONLINEAR: 1. Referring to a storage medium in which any data
point can be accessed or read almost instantly. Examples are a
hard disk, compact disc and MiniDisc. See Random Access. 2.
Referring to an audio device that is distorting the signal.
OCTAVE: The interval between any two frequencies where the upper
frequency is twice the lower frequency.
OFF-AXIS: Not directly in front of a microphone or loudspeaker.
OFF-AXIS COLORATION: In a microphone, the deviation from the
on-axis frequency response that sometimes occurs at angles off
the axis of the microphone. The coloration of sound (alteration
of tone quality) for sounds arriving off-axis to the microphone.
OMNIDIRECTIONAL MICROPHONE: A microphone that is equally
sensitive to sounds arriving from all directions.
ON-LOCATION RECORDING: A recording made outside the studio, in a
room or hall where the music usually is performed or practiced.
OPEN TRACKS: On a multitrack tape recorder, tracks that have not
yet been used, or have already been bounced and are available for
use.
ORTF: Named after the French broadcasting network (Office de
Radiodiffusion Television Francaise), a near-coincident stereo
mic technique which uses two cardioid mics angled 110 degrees
apart and spaced 17 cm horizontally.
OUTBOARD EQUIPMENT: Signal processors that are external to the
mixing console.
OUTPUT: A connector in an audio device from which the signal
comes, and feeds successive devices.
OUT-TAKE: A take, or section of a take, that is to be removed or
not used.
OVERDUB: To record a new musical part on an unused track in
synchronization with previously recorded tracks.
OVERHANG: The continuation of a signal at the output of a device
after the input signal has ceased. Sometimes called ringing.
OVERLOAD: The distortion that occurs when an applied signal
exceeds a system's maximum input level.
OVERTONE: In a complex wave, a frequency component that is higher
than the fundamental frequency.
PAD: See Attenuator.
PAN POT: Abbreviation for panoramic potentiometer. In each input
module in a mixing console, a control that divides a signal
between two channels in an adjustable ratio. By doing so, a pan
pot controls the location of a sonic image between a stereo pair
of loudspeakers.
PARAMETRIC EQUALIZER: An equalizer with continuously variable
parameters, such as frequency, bandwidth, and amount of boost or
cut.
PATCH: 1. To connect one piece of audio equipment to another with
a cable. 2. A setting of synthesizer parameters to achieve a
sound with a certain timbre.
PATCH BAY (PATCH PANEL): An array of connectors, usually in a
rack, to which equipment inputs and outputs are wired. A patch
bay makes it easy to interconnect various pieces of equipment in
a central, accessible location.
PATCH CORD: A short length of cable with a coaxial plug on each
end, used for signal routing in a patch bay.
PEAK: On a graph of a sound wave or signal, the highest point in
the waveform. The point of greatest voltage or sound pressure in
a cycle.
PEAK AMPLITUDE: See Amplitude, Peak.
PEAKING EQUALIZER: An equalizer that provides maximum cut or
boost at one frequency, so that the resulting frequency response
of a boost resembles a mountain peak.
PEAK PROGRAM METER (PPM): A meter that responds fast enough to
closely follow the peak levels in a program.
PERIOD: The time between the peak of one wave and the peak of the
next. The time between corresponding points on successive waves.
Period is the inverse of frequency.
PERSONAL STUDIO: A minimal group of recording equipment set up
for one's personal use, usually using a 4-track cassette
recorder-mixer. Also, a simple 4-track cassette recorder-mixer
for one's personal use.
PERSPECTIVE: In the reproduction of a recording, the audible
sense of distance to the musical ensemble, the point of view. A
close perspective has a high ratio of direct sound to reverberant
sound; a distant perspective has a low ratio of direct sound to
reverberant sound.
PFL: Abbreviation for Pre-Fader Listen. See also Solo.
PHANTOM POWER: A DC voltage (usually 12 to 48 volts) applied to
microphone signal conductors to power condenser microphones.
PHASE: The degree of progression in the cycle of a wave, where
one complete cycle is 360 degrees.
PHASE CANCELLATION, PHASE INTERFERENCE: The cancellation of
certain frequency components of a signal that occurs when the
signal is combined with its delayed replica. At certain
frequencies, the direct and delayed signals are of equal level
and opposite polarity (180 degrees out of phase), and when
combined, they cancel out. The result is a comb-filter frequency
response having a periodic series of peaks and dips. Phase
interference can occur between the signals of two microphones
picking up the same source at different distances, or can occur
at a microphone picking up both a direct sound and its reflection
from a nearby surface.
PHASE SHIFT: The difference in degrees of phase angle between
corresponding points on two waves. If one wave is delayed with
respect to another, there is a phase shift between them of
2[pi]FT, where [pi] = 3.14, F = frequency in Hz, and T = delay in
seconds.
PHASING: A special effect in which a signal is combined with its
phase-shifted replica to produce a variable comb-filter effect.
See also Flanging.
PHONE PLUG: A cylindrical, co-axial plug (usually 1/4-inch
diameter). An unbalanced phone plug has a tip for the hot signal
and a sleeve for the shield or ground. A balanced phone plug has
a tip for the signal hot signal, a ring for the return signal,
and a sleeve for the shield or ground.
PHONO PLUG: A coaxial plug with a central pin for the hot signal
and a ring of pressure-fit tabs for the shield or ground. Also
called RCA plug.
PICKUP: A piezoelectric transducer that converts mechanical
vibrations to an electrical signal. Used in acoustic guitars,
acoustic basses, and fiddles. Also, a magnetic transducer in an
electric guitar that converts string vibration to a corresponding
electrical signal.
PINCH ROLLER: In a tape-recorder transport, the rubber wheel that
pinches or traps the tape between itself and the capstan, so that
the capstan can move the tape.
PING-PONGING: See Bouncing Tracks.
PINK NOISE: A noise signal containing all frequencies (unless
band-limited), with equal energy per octave. Pink noise is a test
signal used for equalizing a sound system to the desired
frequency response, and for testing loudspeakers.
PITCH: The subjective lowness or highness of a tone. The
pitch of a tone usually correlates with the fundamental
frequency.
PITCH CONTROL: A control on a tape recorder that varies the tape
speed, thereby varying the pitch of the signal on tape. The pitch
control can be used to match the pitch of prerecorded instruments
with that of an instrument to be overdubbed. It is also used for
special effects, such as "chipmunk voices," and to play
prerecorded tracks slowly so that fast musical passages can be
overdubbed more easily.
PITCH SHIFTER: A signal processor that changes the pitch of an
instrument without changing its duration.
PLAYBACK EQUALIZATION: In tape-recorder electronics, fixed
equalization applied to the signal during recording to compensate
for certain losses.
PLAYBACK HEAD: The head in a tape recorder that picks up a
prerecorded magnetic signal from the moving tape and converts it
to a corresponding electrical signal. The playback head is not
the same as the sel-sync or sync head.
PLAYLIST: See Edit Decision List.
PLUG: A male connector that inserts into a jack.
PLUG-IN: Software effects that you install in your computer. The
plug-in software becomes part of another program you are using,
such as a digital editing program.
POLAR PATTERN: The directional pickup pattern of a microphone. A
plot of microphone sensitivity plotted vs. angle of sound
incidence. Examples of polar patterns are omnidirectional,
bidirectional, and unidirectional. Subsets of unidirectional are
cardioid, supercardioid, and hypercardioid.
POLARITY: Referring to the positive or negative direction of an
electrical, acoustical, or magnetic force. Two identical signals
in opposite polarity are 180 degrees out-of-phase with each other
at all frequencies.
POLYPHONIC--Describing a synthesizer that can play more than one
note at a time (chords).
POP: 1. A thump or little explosion sound heard in a vocalist's
microphone signal. Pop occurs when the user says words with "p,"
"t," or "b" so that a turbulent puff of air is forced from the
mouth and strikes the microphone diaphragm. 2. A noise heard when
a mic is plugged into a monitored channel, or when a switch is
flipped.
POP FILTER: A screen placed on a microphone grille that
attenuates or filters out pop disturbances before they strike the
microphone diaphragm. Usually made of open-cell plastic foam or
silk, a pop filter reduces pop and wind noise.
PORTABLE STUDIO: A combination recorder and mixer in one portable
chassis.
POST-ECHO: A repetition of a sound, following the original sound,
caused by print-through.
POWER AMPLIFIER: An electronic device that amplifies or increases
the power level fed into it to a level sufficient to drive a
loudspeaker.
POWER GROUND (SAFETY GROUND): A connection to the power company's
earth ground through the U-shaped hole in a power outlet. In the
power cable of an electronic component with a 3-prong plug, the
U-shaped prong is wired to the component's chassis. This wire
conducts electricity to power ground if the chassis becomes
electrically hot, preventing shocks.
PREAMPLIFIER (PREAMP): In an audio system, the first stage of
amplification that boosts a mic-level signal to line level. A
preamp is a stand-alone device or a circuit in a mixer.
PREDELAY: Short for pre-reverberation delay. The delay (about 30
to 150 milliseconds) between the arrival of the direct sound and
the onset of reverberation. Usually, the longer the predelay, the
greater the perceived room size.
PRE-ECHO: A repetition of a sound that occurs before the sound
itself, caused by print-through.
PREFADER/POSTFADER SWITCH: A switch that selects a signal either
ahead of the fader (prefader) or following the fader (postfader).
The level of a prefader signal is independent of the fader
position; the level of a postfader signal follows the fader
position.
PREPRODUCTION: Planning in advance what you're going to do at a
recording session, in terms of track assignments, overdubbing,
studio layout, and microphone selection.
PRESENCE: The audible sense that a reproduced instrument is
present in the listening room. Some synonyms are closeness,
definition, and punch. Presence is often created by an
equalization boost in the midrange or upper midrange.
PRESSURE ZONE MICROPHONE: A boundary microphone constructed with
the microphone diaphragm parallel with, and facing, a reflective
surface.
PREVERB: A special effect in which the reverberation of a note
precedes it, rather than follows it. Preverb is achieved by
playing an instrument's track backwards while adding
reverberation to it, and recording the reverberation on an unused
track. When the tape is reversed so that the instrument's track
plays forward, preverb is heard as the reverberation plays
backwards.
PRINT: To record on tape or disc.
PRINT-THROUGH: The transfer of a magnetic signal from one layer
of tape to the next on a reel, causing an echo preceding or
following the program.
PRODUCTION: 1. A recording that is enhanced by special effects.
2. The supervision of a recording session to create a
satisfactory recording. This involves getting musicians together
for the session, making musical suggestions to the musicians to
enhance their performance, and making suggestions to the engineer
for sound balance and effects.
PROGRAM BUS: A bus or output that feeds an audio program to a
recorder track.
PROGRAM MIXER: In a mixing console, a mixer formed of input-
module outputs, combining amplifiers, and program buses.
PROXIMITY EFFECT: The bass boost that occurs with a single-D
directional microphone when it is placed a few inches from a
sound source. The closer the microphone, the greater the
low-frequency boost due to proximity effect.
PUNCH IN/OUT: A feature in a multitrack recorder that lets you
insert a recording of a corrected musical part into a previously
recorded track by going into and out of record mode as the tape
is rolling.
PURE WAVEFORM: A waveform of a single frequency; a sine wave. A
pure tone is the perceived sound of such a wave.
QUARTER-TRACK: A tape track recorded across one-quarter of the
width of the tape. A quarter-track recorder usually records two
stereo programs (one in each direction).
RACK: A 19-inch-wide wooden or metal cabinet used to hold audio
equipment.
RADIO-FREQUENCY INTERFERENCE (RFI): Radio-frequency
electromagnetic waves induced in audio cables or equipment,
causing various noises in the audio signal.
RANDOM ACCESS: Referring to a storage medium in which any data
point can be accessed or read almost instantly. Examples are a
hard disk, compact disc and MiniDisc.
RAREFACTION: The portion of a sound wave in which molecules are
spread apart, forming a region with lower-than-normal atmospheric
pressure. The opposite of compression.
R-DAT: See DAT.
REAL-TIME RECORDING: 1. Recording notes into a sequencer in the
correct tempo, for later playback at the same tempo as recorded.
2. A recording made direct to lacquer disc or direct to 2-track
without any overdubs or mixdown.
RECIRCULATION (REGENERATION): Feeding the output of a delay
device back into its input to create multiple echoes. Also, the
control on a delay device that affects how much delayed signal is
recycled to the input.
RECORD: To store an event in permanent form. Usually, to store an
audio signal in magnetic form on magnetic tape. Recording is also
possible on hard disk, on compact disc (CD-R), on magneto-optical
disk, MiniDisc, and in RAM.
RECORD EQUALIZATION: In tape-recorder electronics, equalization
applied to the signal during recording to compensate for certain
losses.
RECORDER-MIXER: A combination multitrack recorder and mixer in
one chassis.
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 audio signal.
RECORDING/REPRODUCTION CHAIN: The series of events and equipment
that are involved in sound recording and playback.
REFLECTED SOUND: Sound waves that reach the listener after being
reflected from one or more surfaces.
REGENERATION: See Recirculation.
REGION: In a digital audio editing program, a defined segment of
the audio program.
RELEASE: The final portion of a note's envelope in which the note
falls from its sustain level back to silence.
RELEASE TIME: In a compressor, the time it takes for the gain to
return to normal after the end of a loud passage.
REMIX: To mix again; to do another mixdown with different console
settings or different editing.
REMOTE RECORDING: See On-Location Recording.
REMOVABLE HARD DRIVE: A hard disk drive that can be removed and
replaced with another, used in a digital audio workstation to
store a long program temporarily.
RESISTANCE: The opposition of a circuit to a flow of direct
current. Resistance is measured in ohms, abbreviated [Greek
Omega], and may be calculated by dividing voltage by current.
RESISTOR: An electronic component that opposes current flow.
RETURN-TO-ZERO: See Memory Rewind.
REVERBERATION: Natural reverberation in a room is a series of
multiple sound reflections which makes the original sound persist
and gradually die away or decay. These reflections tell the ear
that you're listening in a large or hard-surfaced room. For
example, reverberation is the sound you hear just after you shout
in an empty gymnasium. A reverb effect simulates the sound of a
room--a club, auditorium, or concert hall--by generating random
multiple echoes that are too numerous and rapid for the ear to
resolve. The timing of the echoes is random, and the echoes
increase in number with time as they decay. An echo is a discrete
repetition of a sound; reverberation is a continuous fade-out of
sound.
REVERBERATION TIME (RT60): The time it takes for reverberation to
decay to 60 dB below the original steady-state level.
REVERSE ECHO: A multiple echo that precedes the sound that
caused it, building up from silence into the original sound. This
special effect is created in a manner similar to preverb.
RFI: See Radio Frequency Interference.
RHYTHM TRACKS: The recorded tracks of the rhythm instruments
(guitar, bass, drums, and sometimes keyboards).
RIBBON MICROPHONE: A dynamic microphone in which the conductor is
a long metallic diaphragm (ribbon) suspended in a magnetic field.
RIDE GAIN: To turn down the volume of a microphone when the
source gets louder, and turn up the volume when the source gets
quieter, in an attempt to reduce dynamic range.
RINGING: See Overhang.
ROOM MODES: See Standing Wave.
RT60: See Reverberation Time.
SAFETY COPY: A copy of the master tape, to be used if the master
tape is lost or damaged.
SAFETY GROUND: See Power Ground.
SAMPLE: 1. To digitally record a short sound event, such as a
single note or a musical phrase, into computer memory. 2. A
recording of such an event.
SAMPLING: Recording a short sound event into computer memory. The
audio signal is converted into digital data representing the
signal waveform, and the data is stored in memory chips, tape or
disc for later playback.
SATURATION: Overload of magnetic tape. The point at which a
further increase in magnetizing force does not cause an increase
in magnetization of the tape oxide particles. Distortion is the
result.
SCRATCH VOCAL: A vocal performance that is done simultaneously
with the rhythm instruments so that the musicians can keep their
place in the song and get a feel for the song. Because it
contains leakage, the scratch-vocal recording is usually erased.
Then the singer overdubs the vocal part that is to be used in the
final recording.
SCRUB: To manually move an open-reel tape slowly back and forth
across a recorder playback head in order to locate an edit point.
Some digital editing software has an equivalent scrubbing
function.
SENSITIVITY: 1. The output of a microphone in volts for a given
input in sound pressure level. 2. The sound pressure level a
loudspeaker produces at one meter when driven with one watt of
pink noise. See also Sound Pressure Level.
SEQUENCE: A MIDI data file of musical-performance note
parameters, recorded by a sequencer.
SEQUENCER: A device that records a musical performance done on a
MIDI controller (in the form of note numbers, note on, note off,
etc.) into computer memory or hard disk for later playback. A
computer can act as a sequencer when it runs a sequencer program.
During playback, the sequencer plays synthesizer sound generators
or samples.
SESSION: 1. A time period set aside for recording musical
instruments, voices, or sound effects. 2. On a CD-R, a lead-in,
program area, and lead-out.
SHELVING EQUALIZER: An equalizer that applies a constant boost or
cut above or below a certain frequency, so that the shape of the
frequency response resembles a shelf.
SHIELD: A conductive enclosure (usually metallic) around one or
more signal conductors, used to keep out electrostatic fields
that cause hum or buzz.
SHOCK MOUNT: A suspension system which mechanically isolates a
microphone from its stand or boom, preventing the transfer of
mechanical vibrations.
SIBILANCE: In a speech recording, excessive frequency components
in the 5 to 10 kHz range, which are heard as an overemphasis of
"s" and "sh" sounds.
SIDE-ADDRESSED: Referring to a microphone whose main axis of
pickup is perpendicular to the side of the microphone. You aim
the side of the mic at the sound source. See also End-Addressed.
SIGNAL: A varying electrical voltage that represents
information, such as a sound.
SIGNAL PATH: The path a signal travels from input to output in a
piece of audio equipment.
SIGNAL PROCESSOR: A device that is used to alter a signal in a
controlled way.
SIGNAL-TO-NOISE RATIO (S/N): The ratio in decibels between signal
voltage and noise voltage. An audio component with a high S/N has
little background noise accompanying the signal; a component with
a low S/N is noisy.
SINE WAVE: A wave following the equation y = sin x, where x is
degrees and y is voltage or sound pressure level. The waveform of
a single frequency. The waveform of a pure tone without harmonics.
SINGLE-ENDED: 1. An unbalanced line. 2. A single-ended noise
reduction system is one that works only during tape playback
(unlike Dolby or dbx, which work both during recording and
playback).
SINGLE-D MICROPHONE: A directional microphone having a single
distance between its front and rear sound entries. Such a
microphone has proximity effect.
SLAP, SLAPBACK: An echo following the original sound by about 50
to 200 milliseconds, sometimes with multiple repetitions.
SLATE: At the beginning of a recording, a recorded announcement
of the name of the tune and its take number. The term is derived
from the slate used in the motion-picture industry to identify
the production and take number being filmed.
SMPTE TIME CODE: A modulated 1,200 Hz square-wave signal used to
synchroinze two or more tape transports or other multitrack
recorders. SMPTE is an abbreviation for the Society of Motion
Picture and Television Engineers, who developed the time code.
SNAKE: A multipair or multichannel mic cable. Also, a multipair
mic cable attached to a connector junction box.
SOLO: On an input module in a mixing console, a switch that lets
you monitor that particular input signal by itself. The switch
routes only that input signal to the monitor system.
SOUND: Longitudinal vibrations in a medium (such as air) in the
frequency range 20 Hz to 20,000 Hz.
SOUND CARD: A circuit card that plugs into a computer, and
converts an audio signal into computer data for storage in memory
or on hard disk. The sound card also converts computer data into
an audio signal.
SOUND MODULE (SOUND GENERATOR): 1. A synthesizer without a
keyboard, containing several different timbres or voices. These
sounds are triggered or played by MIDI signals from a sequencer
program, or by a MIDI controller. 2. An oscillator.
SOUND PRESSURE LEVEL (SPL)--The acoustic pressure of a sound
wave, measured in decibels above the threshold of hearing. The
higher the SPL of a sound, the louder it is. dB SPL = 20 log (P/P
ref), where P = the measured acoustic pressure and P ref = 0.0002
dyne/cm[superscript]2[end superscript]. [ref is subscript]
SOUND WAVE: The periodic variations in sound pressure radiating
from a sound source.
SPACED-PAIR: A stereo microphone technique using two identical
microphones spaced several feet apart horizontally, usually
aiming straight ahead toward the sound source.
SPATIAL PROCESSOR: A signal processor that allows images to be
placed beyond the limits of a stereo pair of speakers--even
behind the listener or toward the sides.
S/PDIF: Sony Philips Digital Interface (IEC 958 Type II). A
digital signal interface format which uses a 75 ohm coaxial cable
terminated with RCA or BNC connectors. See also AES/EBU.
SPEAKER: See Loudspeaker.
SPECIAL EFFECTS: See Effects.
SPECTRUM: The output versus frequency of a sound source,
including the fundamental frequency and overtones.
SPL: See Sound Pressure Level.
SPLICE: To join the ends of two lengths of magnetic tape or
leader tape with tape. Also, a splice is the taped joint between
two lengths of magnetic tape or leader tape.
SPLICING BLOCK: See Editing Block.
SPLIT CONSOLE: A console with a separate monitor-mixer section.
See also In-Line Console.
SPLITTER: A transformer or circuit used to divide a microphone
signal into two or more identical signals to feed different sound
systems.
SPOT MICROPHONE: In classical music recording, a close-placed
microphone that is mixed with more-distant microphones to add
presence or to improve the balance.
STANDING WAVE: An apparently 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.
STEP-TIME RECORDING: Recording notes into a sequencer one at a
time without regard to tempo, for later playback at a normal
tempo.
STEREO, STEREOPHONIC--An audio recording and reproduction system
with correlated information between two channels (usually
discrete channels), and meant to be heard over two or more
loudspeakers to give the illusion of sound-source localization
and depth.
STEREO BAR, STEREO MICROPHONE ADAPTER: A microphone stand adapter
that mounts two microphones on a single stand for convenient
stereo miking.
STEREO IMAGING: The ability of a stereo recording or reproduction
system to form clearly defined audio images at various locations
between a stereo pair of loudspeakers.
STEREO MICROPHONE: A microphone containing two mic capsules in a
single housing for convenient stereo recording. The capsules
usually are coincident.
STUDIO: A room used or designed for sound recording.
SUBMASTER: 1. A master volume control for an output bus. 2. A
recorded tape that is used to form a master tape.
SUBMIX: A small preset mix within a larger mix, such as a drum
mix, keyboard mix, vocal mix, etc. Also a cue mix, monitor mix,
or effects mix.
SUBMIXER--A smaller mixer within a mixing console (or
stand-alone) that is used to set up a submix, a cue mix, an
effects mix, or a monitor mix.
SUPERCARDIOID MICROPHONE: A unidirectional microphone that
attenuates side-arriving sounds by 8.7 dB, attenuates rear-
arriving sounds by 11.4 dB, and has two nulls of maximum sound
rejection at 125 degrees off-axis.
SUPPLY REEL: See Feed Reel.
SURROUND SOUND: A multichannel recording and reproduction system
that plays sound all around the listener. The 5.1 surround system
uses the following speakers: front-left, center, front-right,
left-surround, right-surround, and subwoofer.
SUSTAIN: The portion of the envelope of a note in which the level
is constant. Also, the ability of a note to continue without
noticeably decaying, often aided by compression.
SWEETENING: The addition of strings, brass, chorus, etc. to a
previously recorded tape of the basic rhythm tracks.
SYNC, SYNCHRONIZATION: Aligning two separate audio programs in
time, and maintaining that alignment as the programs play.
SYNC, SYNCHRONOUS RECORDING: Using a record head temporarily as a
playback head during an overdub session, to keep the overdubbed
parts in synchronization with the recorded tracks.
SYNC TONE: See Tape Sync.
SYNC TRACK: A track of a multitrack recorder that is reserved for
recording an FSK sync tone or SMPTE time code. This allows audio
tracks to synchronize with virtual tracks recorded with a
sequencer. A sync track also can synchronize two audio tape
machines or an audio recorder and a video recorder, and can be
used for console automation.
SYNTHESIZER: A musical instrument (usually with a piano-style
keyboard) that creates sounds electronically, and allows control
of the sound parameters to simulate a variety of conventional or
unique instruments.
TAIL-OUT: Referring to a reel of tape wound with the end of the
program toward the outside of the reel. Tape stored tail out is
less likely to have audible print-through.
TAKE: A recorded performance of a song. Usually, several takes
are done of the same song, and the best one--or the best parts of
several--become the final product.
TAKE SHEET: A list of take numbers for each song, plus comments
on each take.
TAKE-UP REEL: The right-side reel on a tape recorder that winds
up the tape as it is playing or recording.
TALKBACK: An intercom in the mixing console for the engineer and
producer to talk to the musicians in the studio.
TAPE: See Magnetic Recording Tape.
TAPE LOOP: An endless loop formed from a length of recording tape
spliced end-to-end, used for continuous repetition of several
seconds of recorded signal.
TAPE RECORDER: A device that converts an electrical audio signal
into a magnetic audio signal on magnetic tape, and vice versa. A
tape recorder includes electronics, heads, and a transport to
move the tape.
TAPE SYNC: A frequency-modulated signal recorded on a tape track,
used to synchronize a tape recorder to a sequencer. Tape sync
also permits the synchronized transfer of sequences to tape. See
also Sync Track.
3-PIN CONNECTOR: A 3-pin professional audio connector used for
balanced signals. Pin 1 is soldered to the cable shield, pin 2 is
soldered to the signal hot lead, and pin 3 is soldered to the
signal return lead. See also XLR-Type Connector.
THREE-TO-ONE RULE: A rule in microphone applications. When
multiple mics are mixed to the same channel, the distance between
mics should be at least three times the distance from each mic to
its sound source. This prevents audible phase interference.
THRESHOLD: In a compressor or limiter, the input level above
which compression or limiting takes place. In an expander, the
input level below which expansion takes place.
TIE: To connect electrically, for example, by soldering a wire
between two points in a circuit.
TIGHT: 1. Having very little leakage or room reflections in the
sound pickup. 2. Referring to well-synchronized playing of
musical instruments. 3. Having a well-damped, rapid decay.
TIMBRE: The subjective impression of spectrum and envelope. The
quality of a sound that allows us to differentiate it from other
sounds. For example, if you hear a trumpet, piano, and a drum,
each has a different timbre or tone quality that identifies it as
a particular instrument.
TIME CODE: A modulated 1200-Hz square-wave signal used to
synchronize two or more tape or disc transports. See also Tape
Sync, Sync Track, SMPTE.
TONAL BALANCE: The balance or volume relationships among
different regions of the frequency spectrum, such as bass,
midbass, midrange, upper midrange, and highs.
GLOSSARY OF RECORDING TERMS
Part 3 of 3
By Bruce Bartlett
TRACK: A path on magnetic tape containing a single channel of
audio. A group of bytes in a digital signal (on tape, on hard
disk, on compact disc, or in a data stream) that represents a
single channel of audio or MIDI. Usually one track contains a
performance of one musical instrument.
TRANSDUCER: A device that converts energy from one form to
another, such as a microphone or loudspeaker.
TRANSFORMER: An electronic component made of two magnetically
coupled coils of wire. The input signal is transferred
magnetically to the output, without a direct connection between
input and output.
TRANSIENT: A short signal with a rapid attack and decay, such as
a drum stroke, cymbal hit, or acoustic-guitar pluck.
TRANSIENT RESPONSE: The ability of an audio component (usually a
microphone or loudspeaker) to follow a transient accurately.
TRANSPORT: The mechanical system in a reproduction device that
moves the media past the read/write heads. In a tape recorder,
the transport controls tape motion during recording, playback,
fast forward, and rewind.
TRIM: 1. In a mixing console, a control for fine adjustment of
level, as in a Bus Trim control. 2. In a mixing console, a
control that adjusts the gain of a mic preamp to accommodate
various signal levels.
TUBE: A vacuum tube, an amplifying component made of electrodes
in an evacuated glass tube. Tube sound is characterized as being
"warmer" than solid-state or transistor sound.
TWEETER: A high-frequency loudspeaker.
UNBALANCED LINE: An audio cable having one conductor surrounded
by a shield that carries the return signal. The shield is at
ground potential.
UNIDIRECTIONAL MICROPHONE: A microphone that is most sensitive to
sounds arriving from one direction -- in front of the microphone.
Examples are cardioid, supercardioid, and hypercardioid.
VALVE: British term for vacuum tube. See Tube.
VIRTUAL CONTROLS: Audio-equipment controls that are simulated on
a computer monitor screen. You adjust them with a mouse.
VIRTUAL TRACK: A sequencer recording of a single musical line,
recorded as data in computer memory. A virtual track is the
computer's equivalent of a tape track on a multitrack tape
recorder.
VU METER: A voltmeter with a specified transient response,
calibrated in VU or volume units, used to show the relative
volume of various audio signals, and to set recording level.
WAVEFORM: A graph of a signal's soun | 
