Tactile Perspective / Audio Terminology Glossary

[Mr Latte]

This thread attempts to simplify terms often used but not so well understood. I have gathered this information from various sources to help the community. Please appreciate I am neither an audio engineer or audio expert but enthusiast only.

Terms listed are ones I believe to be most relevant in considering audio tactile, including Simvibe and frequencies in general. Also covering some technical aspects of what additional hardware and audio tuning via specialised DSP or audio DAW software may bring.

See below also in last post for useful links.


Audio Terms Glossary

B

Balance
The relative level of two or more instruments in a mix, or the relative level of audio signals in the channels of a stereo recording.
To make the relative levels of audio signals in the channels of a stereo recording even.

Balance Control
A control on a stereo amplifier that when moved clockwise will make the right channel louder (and the left channel softer) and will do the reverse when moved counter-clockwise.

Balanced
Having a pleasing amount of low frequencies compared to mid-range frequencies and high frequencies.
Having a pleasing mixture of the various instrument levels in an audio recording. Having a fairly equal level in each of the stereo channels.
A method of interconnecting electronic gear using three-conductor cables.

Balanced input/output
A “balanced” connection is one that has three wires to move the signal. One is a ground, and the other two (called conductors) carry signals of equal value. This is why they are called balanced. Low Z cables and connections are the most common example.

Bandwidth
The range of frequencies over which a tape recorder, amplifier or other audio device is useful.
The range of frequencies affected by an equalization setting.


C

Cancellation
A shortening of the term Phase Cancellation (the energy of one waveform significantly decreasing the energy of another waveform because of phase relationships at or close to 180 degrees).

Clipping
Distortion of a signal by its being chopped off. An overload problem caused by pushing an amplifier beyond its capabilities. The flat-topped signal has high levels of harmonic distortion which creates heat in a loudspeaker and is the major cause of loudspeaker component failure.

Crossover
A set of filters that “split” the audio signal into two or more bands (two or more signals, each of which have only some of the frequencies present).

Crossover Frequency
The frequency that is the outer limit of one of the bands of a crossover.

Crosstalk
Leakage of an audio signal into a channel that it is not intended to be in, from an adjacent or nearby channel.

Centre Frequency
The frequency of the audio signal that is boosted or attenuated most by an equalizer with a peak equalization curve.

Channel
A single path that an audio signal travels or can travel through a device from an input to an output.

Compression Ratio
How many dB the input signal has to rise above the threshold for every one dB more output of a compressor or limiter.

Compressor
A signal processing device that does not allow as much fluctuation in the level of the signal above a certain adjustable or fixed level.
Cut-Off Frequency (Turnover Frequency)
The highest or lowest frequency in the pass band of a filter.
Cut-off Rate (Slope)
The number of dB that a filter reduces the signal for each octave its frequency past the filter’s cut-off frequency (outside of the pass band).

Cycle
An alternation of a waveform which begins at a point, passes through the zero line, and ends at a point with the same value and moving in the same direction as the starting point.

Cycles Per Second
A unit used in the measure of frequency, equivalent to Hertz. Cycles Per Second is an outdated term replaced by Hertz in 1948.


D

Decibel (dB)
Relative measurement for the volume (loudness) of sound. Also used to measure the difference between two voltages, or two currents. A numerical expression of the relative loudness of a sound.

Distortion
Usually undesirable result of overloading sound equipment. Reducing the levels can remedy the situation.

 

[Mr Latte]

E

Equaliser (Parametric, Graphic)
This is used to filter out and adjust specific frequencies where you have the most control over the overall sound.

Equalisation
The process of adjusting the tonal quality of a sound. A graphic equaliser provides adjustment for a wide range of frequency bands and is normally inserted in the signal path before the amplifier.
Any time the amplitude of audio signals at specific set of frequencies are increased or decreased more than the signals at other audio frequencies.

F

Filter
A device that removes signals with frequencies above or below a certain point called the cut-off frequency.
An equaliser section, used in this sense because filters are used with other components to give an equalizer its frequency response characteristics.
The action of removing signals of some frequencies and leaving the rest.

Frequency
The number of cycles of a waveform occurring in a second (Hz).
Practically speaking, high frequency means high pitch and low frequency means low pitch.

Frequency Range
The range of frequencies over which an electronic device is useful or over which a sound source will put out substantial energy.

Frequency Response
How sensitive an electronic device (mic, amplifier, speaker, etc.) is to various frequencies, often communicated with a graph.

Full Range
Describes a sound which covers all audible frequency ranges. As in “full range speaker cabinets.”

Fundamental
The tuned frequency and (almost always) the lowest frequency that is present.

G

Gain
Used to set input levels of the separate channels to relatively equal positions.
The amount of increase in audio signal strength often expressed in dB.

Gain Control
A device that changes the gain of an amplifier or circuit, often a knob that can be turned or a slide that can be moved up and down.

Gain Reduction
The working of a limiter or compressor reducing gain.

Graphic Equaliser
A device with several slides controlling the gain of audio signal present which is within one of several evenly spaced frequency bands (spaced according to octaves).

 

[Mr Latte]

H

Harmonics
Integer multiples of a fundamental frequency, the fundamental itself being the first harmonic, its first overtone the second harmonic.

Headroom
The level difference (in dB) between normal operating level and clipping level in an amplifier or audio device.
The difference, in decibels, between the peak and RMS levels in program material.

Hertz
The unit of frequency. Equivalent to cycles per second. Abbreviation: Hz.

High-Pass Filter
A device that rejects signals that are below a certain frequency (called the cut-off frequency) and passes signals with frequencies that are higher.

Hum
The power line current accidentally induced or fed into electronic equipment.

Hz (Hertz)
An abbreviation for the term Hertz (the unit of frequency).
Unit of frequency equivalent to the number of cycles per second.


I

Impedance
A term for the electrical resistance found in a/c circuits. Affects the ability of a cable to transmit low level (e.g. sound) signals over a long distance. Measured in Ohms. Speakers are rated according to power handling capabilities (Watts, W) and impedance (Ohms).
The total opposition offered by an electric circuit to the flow of an alternating current of a single frequency. It is a combination of resistance and reactance and is measured in ohms.

Input
The jack or physical location of where a device receives a signal.
The signal being received by a device.
The action of receiving a signal by a device.

I/O
Short for “Input/Output’

Isolation
A containing of the sound wave in a certain area so that it will not leak into other areas.


L

Level
The amount of signal strength; the amplitude, especially the average amplitude.

Limiter
A device which reduces gain when the input voltage exceeds a certain level.

Line In (Input, return)
Where a signal enters the board or component.

Line Input
An input designed to take a line level signal.

Line Level
An amplified signal level put out by an amplifier and used as the normal level that runs through the interconnecting cables in a control room.

Line Out (Line Output)
Any output that sends out a line level signal.

Linear
The condition of obtaining a change at the output of the device which is proportional to the change occurring at the input.

Line Out (Output, Send)
Where a signal leaves the board or component.

Linearity
The extent to which any signal handling process is accomplished without amplitude distortion.

Loudness
How loud something sounds to the ear.
Causing equal volume changes at all frequency ranges including frequency response changes at lower operating levels to compensate for the Fletcher Munson effect.

Low End
A slang term for bass-frequency signals (below 250 Hz).

Low Frequencies
Any audio or audible frequency below 1kHz.
The range of bass frequencies below approximately 250 Hz.
In Simvibe relevant to bass frequencies approx below 30 Hz

Low-Pass Filter
A device that rejects signal above a certain frequency and passes signals that are lower in frequency.

 

[Mr Latte]

M

Mixer
A console, or another device that blends audio signals into composite signals and has a small number of outputs.

Monitor
In audio, to listen.
To indicate with a meter or light the conditions especially level and overload.
A device to listen or observe.

Mono
Shortened from Monophonic and meaning that there is only one sound source or the signal was derived from one sound source.

Ms
An abbreviation for milliseconds (1/1000th of a second)


O

Octave
A difference of pitch where one tone has a frequency that is double or one-half of the frequency of another tone.

Ohm
The unit of opposition to current flow.

Output
The jack or physical location of where a device sends out a signal.
The signal put out by a device.

Output Level
The signal level at the output of a device.

Overload
To put too much signal level into thereby causing distortion

Overload Indicator
An LED on a channel of a console/amplifier that shows that the input or other part of the circuit is receiving an overload.

Overtones
The harmonics of an instrument’s sound minus the fundamental frequency.


P

Parametric EQ
An sequalier in which all of the parameters of equalisation can be adjusted to any amount including a) center frequency b) the amount of boost or cut in gain and c) the bandwidth.


Peak
The highest point in the audio waveform.

Peak Indicating Meter
A meter which reads the absolute peak level of the waveform.

Phase
The amount by which one sine wave leads or lags a second wave of the same frequency. The difference is described by the term phase angle. Sine waves in phase reinforce each other, those out of phase cancel.

Pink Noise
A random noise used in measurements, as it has the same amount of energy in each octave.

Pure Tone
A tone without harmonic frequencies except for the fundamental frequency and with a sine wave shape.

 

[Mr Latte]

Q

Q
The sharpness of the peak response in an equalization circuit.

Quad (Quadraphonic)
A system of four channel sound where the channels are designated as left front, left back, right front, and right back.


R

RCA Plug (jack)
The common audio connector found on most stereo systems.

Resonance
The effect produced when the natural vibration frequency of a body is greatly amplified by reinforcing vibrations at the same or nearly the same frequency from another body.
The prolonging of the sound at a certain frequency and the tendency of something to vibrate at a particular frequency after the source of energy is removed.

Resonant
Tending to pass signals of a certain frequency or narrow range of frequencies more than signals of other frequencies.
Physical properties that tend to reinforce the energy at certain frequencies of vibration.

Resonant Frequency
The frequency at which a physical item tends to vibrate after the source of energy (causing the vibration) is removed.

Resonate
To vibrate at the resonant frequency.
To linger on, as in reverberation, said of sound in a room or used to describe a room/area that has reverberation with a long reverb time.

Reverberation
The persistence of a sound after the source stops emitting it, caused by many discrete echoes arriving at the ear so closely spaced in time that the ear cannot separate them.

Roll-Off
The reduction of signal level as the frequency of the signal moves away from the cut-off frequency, especially when the cut-off rate is mild.

RMS
Abbreviation for root mean square. The effective value of a given waveform is its RMS value. Acoustic power is proportional to the square of the RMS sound pressure.
The effective average value of an AC waveform.

 

[Mr Latte]

S

Sensitivity
Volume of sound delivered for a given electrical input.
The output level produced by a standard amount of sound pressure level

Shelf
A frequency response of an equalization circuit where the boost or cut of frequencies forms a shelf on a frequency response graph. A High-Frequency Shelf control will affect signal levels at the set frequency and all frequencies higher than it. A Low-Frequency Shelf control will affect signal levels at the set frequency and all frequencies lower than it.

Signal-to-Noise Ratio
The amount of dB lower the noise is as compared to the signal.

Sine Wave
The waveform that would be obtained from a vibrating source that was vibrating at just one frequency (making a pure tone).

Sound Level
A shortening of the term Sound Pressure Level (a measure of the sound pressure created by a sound)

Speakon Connector
A type of shielded, locking multipin speaker connector which can safely carry the high currents from an amplifier needed to drive large speaker systems. Available in 4- or 8-way types, and ideal for bi-amplified systems. The cable version of the connector is male, and the panel mount connector is female.


Square Wave
A wave shape where the voltage rises instantly to one level, stays at that level, instantly falls to another level and stays at that level, and finally instantly rises to its original level to form each cycle.

Stereo
A recording or reproduction of at least two channels where positioning of instrument sounds left to right can be perceived.

Stereo Image
The perception of the different sound sources being far left, far right or any place in between.


T

Test Tones
A recording of several single-frequency tones at the beginning of a tape reel at the magnetic reference level that will be used to record the program.

THD
An abbreviation for Total Harmonic Distortion.

Threshold
The level at which a dynamics processing unit will begin to change gain.

Threshold Control
A control on a dynamics processing device that adjusts the threshold level (the level at which a dynamics processing unit will begin to change gain).

Tone
Any single-frequency signal or sound.
The sound quality of an instrument’s sound relative to the amount of energy present at different frequencies.

Tone Generator
A device or software, which puts out test tones at various frequencies for testing purposes.

Transducer
A device which converts energy from one medium to another.
Any of various devices that transmit energy from one system to another, Loudspeaker transducers convert electrical energy into mechanical motion.

 

[Mr Latte]

V

Volume
A common, non-technical term meaning Sound Pressure Level, and loosely applied to also mean audio voltage level.
Short for the term Volume Control (a gain control of an amplifier).

VU Meter (VU – Volume Unit)
Pointer and scale meter which indicates the average level of a signal. Misses any transients and spikes that lead to a clipped signal.


W

Watt
Unit of electrical power derived from the current (or “quantity” of electricity) multiplied by the voltage (or “pressure” at which the current is delivered).

Wave
A continuous fluctuation in the amplitude of a quantity with respect to time.

Waveform
The shape made by the fluctuations of a quantity over time.

Wavelength
The length of one cycle
The distance measured in the direction of progression of a wave, from any given point characterized by the same phase.

Weighting
An equalization curve used in audio tests that compensate for the Fletcher Munson Effect at various levels.

White noise
A random noise used in measurements, as it has the same amount of energy at each frequency.
A random energy where there is an energy distribution so that the amount of energy is the same for each cycle, causing the noise level to increase with frequency.


X

XLR Connector
A common 3 pin connector used in balanced audio connections.
A microphone Cable.

 

[Mr Latte]

Other Links & Resources

Testing 1212 Full Glossary

Geoff The Grey Geek

Online Tone Generator

Esser Audio.com

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Fletcher–Munson curves

A-Weighting
Used by many manufacturers of amplifiers in specifications

 

[SOLO59]

Great work Mr. Latte! Very useful info here. I hope your work will be made available here on the forums for everyone to read when they/we need some guidance. Thanks man!

 

[signman]

Yes thank you for this,

 

[paulopsx2]

usefull. thanks.