A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z
A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z
70-Volt System - See Constant Voltage System.
Sabin - This is not complete yet.
Sampling Frequency Or Sampling Rate - This is not complete yet.
Sampling (nyquist)theorem - This is not complete yet.
Scene - In theatrical sound, the term usually refers to a computerized "snapshot" of presets in a mixing console or other processing device. For instance, a set of input and output levels could be saved into a scene memory in a console for later recall by the operator. Very similar to the term, "Cue," as it applies to advanced mixing consoles such as the Cadac.
Semitone - This is not complete yet.
Send - On a mixing desk, an output separate from the main outputs which are designed to feed an external signal processing system; generally, each input channel will have the necessary controls and electronics to perform this task. See Auxiliary.
SensitivityI - This is not complete yet.
Servo-loop; -locked Loop; -mechanism - This is not complete yet.
Shield - In electronics primarily in an audio cable or in an audio enclosure a shield is a conductive enclosure that protects against electromagnetic and electrostatic fields. In audio, unwanted EMF fields can create unwanted noise in audio circuits, usually found as a hum or a buzz. Most commonly, a cable shield comprised of a braided copper strands wrapped around the actual audio signal conductors; other shields primarily those found in installation cable consist of a wrap of foil encircling the inner conductors. Audio enclosures usually use some form of metal enclosure that is connected to ground.
Shock Mounting - A physical system that mechanically isolates a piece of equipment of pieces of equipment from unwanted vibration. Most often found in rack cases, to isolate rack-mounted equipment from physical vibration found in shipping, transportation, or accidents. Shock mounts are also found in microphone hardware to isolate microphones from similar vibrations and noises. Some types incorporate a web of elastic to suspend the microphone within a silent, rubber framework.
Show Relay - A tertiary sound system, sometimes installed in a given house, whereby the program of the show is picked up either via a microphone in the house or through the mixing desk and delivered backstage to dressing rooms, show control areas, or technical booths.
Sibilance - Refers to "s," "sh," or "ch," vocal sounds, which live in the 5 to 10 kHz frequency range.
Sidechain - Often found in dynamic processors, such as compressors, expanders, and gates-- usually those employing a voltage-controlled-amplifier, or VCA, the sidechain is typically a second signal path which influences the control voltage of the VCA, and thus, the main signal.For example, de-essers route the audio signal through the VCA inputs and outputs. A copy of the original signal is sent to the sidechain input with the offensive frequencies boosted. As the sidechain input senses high amplitude signals over a specified threshold, the resultant control voltage is sent to the VCA and the VCA is told to reduce the overall level of the output.
Signal to Noise Ratio - This is not complete yet.
Signal To Noise Ratio - This is not complete yet.
Silicon Controlled Rectifier - A type of dimmer used in lighting systems that "cuts" or "clips" that AC waveform. Many older types of SCR dimmers can cause undesirable interference in sensitive audio cables if the cables are run in close proximity to the dimmers.
Simple Harmonic Oscillator - Defined as smooth, regular vibrational motion at a single frequency. It is easily illustrated by a mass attached to a spring; in absence of external forces, a mass on a spring will oscillate at a single frequency without change in waveform.
Sine Wave - This is not complete yet.
Skin Effect - The tendency of high-frequency current to travel near the outside of an electric conductor rather than through the cross section of the conductor. Effectively, the result of this phenomenon is that the resistance of the wire increases as the frequency increases, but it is not thought to influence the relatively low-frequencies of the audio spectrum, except by audio purists.
Slew Rate - This is not complete yet.
Slope - This is not complete yet.
SMPTE - This is not complete yet.
Snake - A term given to a construction of multicore audio cable, terminated at both ends, which is designed to facilitate installation of many runs of audio cable. It is usually found as a box, called a stage box, with a number of audio connectors that is either wired into a multipin connector or hardwired to a multicore trunk of some length, which, at the other end, terminates into a fan-out of corresponding connectors. It can be thought of as a number of microphone cables run together in a smaller, more portable, package.
Soft Knee (Compression) - This is not complete yet.
Solo - A function found on some mixing desks, usually multitrack recording desks, on individual input channels. The solo switch operates in the opposite fashion of a mute switch-- solo mutes all channels except the one in solo mode, and generally affects only the audio through specific outputs, such as headphone jacks or control room outputs, so as not to affect a recording mix or the live sound. Most of the time, the solo feed is post-fader, and some mixing desks allow for a "solo-in-place" function, in which the audio signal appears in the outputs in its properly panned location.Compare with PFL and AFL.
Sound - This is not complete yet.
Sound Pressure Level - This is not complete yet.
Spaced Omni - A microphone placement system designed for stereo recording in which two omnidirectional microphones are placed several feet apart in front of the sound source. Mic placement (i.e. distance from the stage) is crucial in balancing ambient sound with the direct sound source. Often used in orchestral recording.
Speakon - A type, and trademark, of a multiconductor connector developed by the Liechtenstein-based company Neutrik specifically used for loudspeaker interconnection. The connectors have become very popular because of their reliability, durability, ability to handle large power sources, lockability, and their relative low cost compared to other connectors developed for loudspeaker applications. The chassis mount connector found on the amplifier output or loudspeaker input always appears as a male version (although it looks like it should be a female connector), and the cable end connectors are always female (although they look like they should be a male connector). Panel mount connectors are available in four-pole and eight-pole varieties, whilst cable-end connectors are available in two-, four-, and eight-pole versions.
Speakon - A type, and trademark, of a multiconductor connector developed by the Liechtenstein-based company Neutrik specifically used for loudspeaker interconnection. The connectors have become very popular because of their reliability, durability, ability to handle large power sources, and their relative low cost compared to other connectors developed for loudspeaker applications. The chassis mount connector found on the amplifier output or loudspeaker input always appears as a male version (although it looks like it should be a female connector), and the cable end connectors are always female (although they look like they should be a male connector). Panel mount connectors are available in four-pole and eight-pole varieties, whilst cable-end connectors are available in two-, four-, and eight-pole versions.
Speed of Sound - The speed of sound is defined as 331.45m/s at 0 degrees Celsius. Helpful in determining the wavelength of a particular frequency or set of frequencies.
Standing Wave - This is not complete yet.
Star Ground - This is not complete yet.
Stereo Pair - A coincident pair of microphones with their axes of maximum response at an angle of 90 degrees.
Subgroup - Also "Group," "Mix Group," "Mix Buss," "Sub Buss," "Submix." A portion of the output section of a mixing desk in which one or more input signals are gathered together and treated as a single set, which can be processed more efficiently and fed as a combination to other sets of outputs.See Mixers for a more in-depth explanation.
Subsonic - Physics: defined as having or relating to a speed lower than the speed of sound in a given medium. Do not confused with "infrasonic," which refers to frequencies below the human hearing range.
Subwoofer - A type of loudspeaker designed specifically to reproduce very low frequency sounds, usually those under 150 Hz. Customarily seen as large cabinets located on the floor, with one or two 15 or 18-inch low-frequency drivers, although it has been proven by some industry pioneers that size does not always matter. Although there are very few naturally-occurring sounds that require a frequency response below 40 Hz, special effects in both theatre and film often make good use of the subwoofer.
Supercardioid - A microphone pickup pattern characterized by increased sensitivity at the front of the microphone (moreso than a standard cardioid microphone, but less than a hypercardioid microphone), and better rejection towards the left-rear and right-rear positions. The supercardioid pattern has a smaller lobe at the rear than the hypercardioid pattern.
Supersonic - Physics: defined as having or relating to a speed greater than the speed of sound in a given medium. Do not confused with "ultrasonic," which refers to frequencies above the human hearing range. The Concorde (British Aerospace) is a supersonic aircraft. A dog whistle produces ultrasonic frequencies.
Sweet Spot - In a stereo loudspeaker arrangement for playback, such as in a studio or home-listening room, it is the location in which the listener is equidistant from each loudspeaker, often defined as the apex of an isosceles triangle formed by the two loudspeakers and the listener.The term can also be applied to studio playback systems for surround sound, in which the listener is equidistant from the left, right, rear left, and rear right loudspeakers.
A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z
Talkback - A feature often found on recording desks, and occasionally on reinforcement desks which enables the engineer to communicate with onstage personnel or to the musicians. Some desks are equipped with built-in microphones, and some have a separate microphone input to accommodate the talkback microphone, and many desks have comprehensive output routing options, allowing the engineer to communicate with individual people or a variety of people at once.
Terminal Strip - A series of electrical connections usually located on the rear of audio equipment, usually with some sort of screw terminals or punch-terminals, arranged along a strip to semi-permanently interconnect components. Many older pieces of studio and broadcast equipment used barrier strips because of their reliability- a single conductor was wound around a screw terminal and tightened down- and their cost. These days, terminal strips can still be found on contractor-grade equipment designed for permanent installation.
Thd+n (total Harmonic Distortion Plus Noise) - This is not complete yet.
THD (Total Harmonic Distortion) - This is not complete yet.
Third-octave - Refers to frequencies spaced every three octaves. For example, the third octave above 500 Hz is 4 kHz (500 Hz is the fundamental, the next octave is 1 kHz, then 2 kHz, then 4 kHz). This term is commonly misused to refer to one-third octave.
Threshold - A parameter found on many dynamic processors, such as compressors, limiters, and noise gates, the user-adjustable setting adjusts at what level the processor will do whatever it is it is supposed to do. For instance, on a compressor, when the signal input level exceeds the set threshold level, the compressor will begin to compress. On a noise gate, the threshold level defines the minimim input level required to allow the gate to pass signal.
Threshold of feeling - The minimum SPL of a pure tone which creates the physical sensation of feeling in the ear. About 120dB SPL.
Threshold of hearing - The minimum sound pressure level of a pure tone that can be perceived by a person with good hearing. A sound pressure of 20x10^-6 pascals is defined as 0dB SPL.
Threshold of pain - The minimum sound pressure level of a pure tone which causes a sensation of pain in the ear. About 140dB SPL.
Timbre - Pronounced "tambour" as in "tambourine," it is the subjective auditory sensation or "color" of a sound by which two sounds with the same loudness and pitch can be distinguished. Timbre is comprised of all sorts of sound qualities-- transient attack, decay, harmonic content, envelope, overtone structure, and more.
Time Aligned - This is not complete yet.
Time Alignment - This is not complete yet.
TNC - Connector: a type of coaxial connector, which is a threaded version of a BNC connector.
Tone - This is not complete yet.
Tone Controls - Refers to a two-band shelving equalizer offering attenuation and amplification control over only high and low frequencies. Commonly found in car stereo equipment and low-end home audio components.
Transducer - A transducer is defined as a device which converts an input signal into an output signal of a different energy form. In sound, we are concerned with the transfer of acoustic sound pressure energy into electrical energy, and back again. Microphones, loudspeakers, tape heads, and phonograph needles are examples of different types of transducers.
Transform Switch - A term applied to a function on DJ mixers by which the source input can be quickly switched on and off. Originally designed as a switch to select between two different inputs as the channel source, DJs used it to quickly gate the sound source. Newer DJ mixers include an actual pushbutton switch for the sole purpose of muting the source material.
Transformer - This is not complete yet.
Transient - This is not complete yet.
Transient Response - This is not complete yet.
Transistor - An solid-state electrical component designed to amplify. See Electrical Engineering text.
Transondent - A not-very-often-used word meaning "acoustically transparent"-- describing a material that does not affect the acoustic signal. Microphone pop-filters and loudspeaker grills should be transondent for best performance.
Trim - A potentiometer found on most mixing desks, often labeled "Gain," which dictates the level of gain in the preamplifier stage of an input channel. See Gain.
TRS - Abbrev. f. "Tip-Ring-Sleeve." Connectors- a term used to describe 1/4" balanced connectors, also called "phone" or 1/4" connectors, although the terms "phone" and 1/4" do not explicitly define a three-conductor connector. The TRS connector is often used for balanced connections in which XLR connectors are too expensive or too large; most commonly, the positive side of the balanced line is connected to the tip, the negative side to the ring, and the shield to the sleeve. TRS connectors are also often used in an unbalanced fashion for stereo equipment (left positive is the tip, right positive is the ring, and ground is the sleeve), or for insert points on mixing desks in which the tip is used as the send positive, the ring as the return positive, and the sleeve is used as the ground.
TS - Abbrev. f. "Tip-Sleeve." Connectors- a term used to describe 1/4" unbalanced connectors, also called "phone" or 1/4" connectors, although the terms "phone" and 1/4" do not explicitly define a two-conductor connector. The TS connector is inexpensive to use when an unbalanced connection is desired. The connector is generally found with the positive signal wired to the tip, and the negative signal carried through the shield wired to the sleeve. Most widely found on unbalanced line-level signals, but can be found on monaural headphones and occasionally as loudspeaker interconnects.
TT, or Tiny-Telephone - A description of patch cables and one of the primary types of connectors found on patchbays. The connector itself resembles a 1/4" phone plug, but it is slightly shorter and narrower, making it possible to squeeze more patch points into a given rack space than with 1/4" connectors. Also called Bantam connectors.
Tweeter - A loudspeaker component designed specifically to reproduce high frequencies. Compression Drivers and Dome Tweeters are two different types of tweeters.
Twisted Pair - Refers to a cable construction in which two center conductors are twisted together. Originally (and still) used by the telecommunications industry, twisted pair construction provides some immunity to induced noise when connected to a balanced input due to the way in which the electromagnetic fields interact. All balanced audio cables are twisted-pair cables with a shield, which further protects the signal being transmitted from introduced noise. Data cables, too, use twisted pair cables for transmission.
Twofer - Getting its name from the lighting industry, a twofer is another name for a y-cable, an adaptor cable constructed with either one output and two inputs, or two outputs and one input, wired in parallel. It allows the passive splitting of one output signal into to devices, or the passive splitting of two output signals into one input. Most audio signals prefer using a dedicated active splitter with amplifiers, such as a distribution amp, but using a twofer is very cost effective and simple. Too much twofering can and undoubtedly will lead to signal degradation.
Ultrasonic - Refers to frequencies above the range of human hearing (considered to be 20 kHz). Do not confuse with "Supersonic," which is defined as a speed faster than the speed of sound.
Unbalanced - An audio wiring scheme referring to an electrical (audio) signal having only two "legs", but one "leg" is the ground or shield. Any noise induced into the cable will make its way into the audio signal because there is no functionality by which induced common-mode noise can be rejected, although the construction and interconnection of an unbalanced circuit is cheaper. In general, avoid long lengths of unbalanced lines to minimize noise potential.Compare with Balanced interconnection, and also see Floating Unbalanced Line.
Unidirectional - In reference to microphone pickup patterns, a pickup pattern in which the microphone is more sensitive to sounds arriving from one direction than from others. It is a description that applies to cardioid, hypercardioid, and supercardioid microphones.
Unity Gain - A condition in a sound system or component in which the output level is equal to the input level-- there is no amplification or attenuation, or a gain of 0dB has been achieved. Operational amplifiers operating at unity gain do the least amount of work and introduce the least amount of noise into the circuit; this situation is optimal for setting proper levels and setting proper gain staging.
Voice Coil - A part of the construction of a dynamic loudspeaker component, the voice coil is a winding of thin wire wound around a cylinder that is affixed to the diaphragm of the loudspeaker. The voice coil is placed within a magnetic field generated by the loudspeaker driver's permanent magnet, and as current travels through the wire, differences in magnetic fields propel the voice coil forward and backwards, producing sound.
Volt - This is not complete yet.
Volt-Ampere - Also "Volt-Amp," and abbrev. "VA." It is the unit for the product of voltage and current (hence the name). While very basic electricity principles dictate that power, measured in Watts, is also the product of voltage and current, this is only true in DC circuits in which there is no circuit inductance or capacitance, which changes the phase of the current and reduces the actual "real" power available. Thus, in AC circuits, the Volt-Ampere measurement will be slightly greater than the Wattage.
Voltage - Voltage is the measure of electrical force between two points that causes a current to flow. It is measured in "Volts,"abbrev. "V," and is named after Alessandro Volta, a Swiss-Italian scientist who played with electrical currents and dead frogs. The most common analog by which to illustrate voltage is via household plumbing: voltage is akin to water pressure, which is available to do work, but does not do work unless a circuit is complete so that the water will actually flow.
Voltage Controlled Amplifier (VCA) - A relatively common piece of electrical circuitry found in many audio components. It is an amplifier circuit whose gain is controlled by an external voltage, as opposed to, say, a potentiometer. For instance, a control voltage of 0VDC may represent "off" to a VCA, and with this instruction the VCA will not produce any output, and a control voltage of +10VDC may represent "full" to a VCA, in which case this VCA circuitry will produce a given amount of gain.VCAs are commonly found in analog synthesizers to create different volume changes over a period of time. VCAs are also at the root of dynamic processors, such as compressors, expanders, noise gates, and de-essers. De-essers, for example, route the audio signal through the VCA and the control voltage applied is inversely proportional to the same audio signal with the offensive frequencies boosted. As the control circuitry senses high-amplitude signals over a specified threshold, the control circuitry sends a control voltage to the VCA which tells the VCA to reduce the level of the output.VCAs are also a common control component of many mixing desks. Instead of a series of input faders with audio faders, in which the actual audio signal travels through the fader unit, the input faders merely control a specified voltage range which tell circuitry, located somewhere else in the mixing desk. In addition to avoiding potential noise problems with audio faders, this system also provides for an easy method by which an operator can control a series of input faders with a single master fader. A master fader, assigned to a series of input faders, merely uses a master control voltage, sent to all assigned faders, to control the VCA circuitry in each individual input.
Vu Meter (volume Units) - This is not complete yet.
Watt - A metric unit of electrical or mechanical power defined as one Joule per second. The Joule is a measurement of energy, and thus power, given the time portion, is the rate of doing work. In audio, the watt is commonly used to describe the power handling requirements or capabilities of loudspeakers and components.
Waveform - Physics: the waveform of a signal, be it electrical or acoustic, is a graph of its instantaneous amplitudes versus time. In sound, we deal with periodic waveforms, waveforms that repeat themselves after a given amount of time, and these graphs can be plotted on a cartesian graph in which the Y-axis represents amplitude, in decibels or volts, and the X-axis represents time.
Wavelength - Physics: the distance between corresponding parts of a periodic waveform, and denoted by the Greek lower-case Lambda symbol. For instance, given a sine wave, it is the distance between one peak and the next corresponding peak. Every frequency has a different wavelength, and may be found by dividing the speed of sound (334 meters/second at sea level) by the frequency. L = 334 / f.
Wedge - Aside from that thing that seems to be driven into my head on a regular basis, or something you eat, "wedge" usually refers to a specially-constructed loudspeaker cabinet, shaped kind of like a wedge and placed on the floor for stage foldback.
Weighting - This is not complete yet.
Weighting - This is not complete yet.
White Noise - A random noise source, electronically generated, having equal energy (amplitude) per frequency, in contrast to pink noise, which contains equal energy per octave. White noise tends to sound brighter due to the human ear's frequency response curve. Analogous to white light, which contains equal amounts of visible frequencies.
Windscreen - A microphone accessory, usually built onto a handheld microphone or available as a separate accessory for a lavalier microphone, which is constructed out of a metal screen which is acoustically transparent. Not only does the windscreen prevent excessive wind noise from reaching the diaphragm of the microphone, but it often protects the microphone in case of droppage.
Woofer - The loudspeaker component designed to reproduce low-frequencies.
Working Distance - Defined as the distance between the miced sound source and the microphone.
X - The electronic symbol for reactance - the imaginary part of impedance. See "Z".
X-Y Pair, X-Y Stereo - A stereo microphone placement technique which employs a coincident pair of cardioid microphones with their axes at anywhere from 90 - 135 degrees from each other. The capsules must be coincident, or as near to the same point as possible, in order to achieve true X-Y Stereo-- they are often positioned one on top of the other to achieve minimal distance. X-Y Stereo is often used in broadcast recording, a situation in which the stereo signal may be summed to mono on older listening equipment. Because there is very little phase difference between the two microphones, summing them creates an acceptable mono signal.
XLR - A type of audio signal connector designed and trademarked by ITT-Cannon. The connector specifications dictate a circular connector, lockable, where ground (pin 1) makes first contact to dissipate any static or induced EMF. Male connectors have pins protected by a metal shell. Three-pin XLR connectors are by far the most common style, used for microphone level audio signals, line level audio signals, and balanced digital signals. Configurations can come with as many as seven pins for special signal transfers, such as intercom, data, or power.Sorry, Virginia, but "XLR" does not stand for anything-- it was Cannon's original part number designation. The Switchcraft A, B, C, D, and E-series connectors, and Neutrik's NC-series connectors are all compatible with the XLR standard.
Y - The electronic symbol for admittance - the inverse of impedance. (See "Z".)
Y cable - An adaptor cable constructed with either one output and two inputs, or two outputs and one input, wired in parallel. It allows the passive splitting of one output signal into to devices, or the passive splitting of two output signals into one input. Most audio signals prefer using a dedicated active splitter with amplifiers, such as a distribution amp, but using a y cable is very cost effective and simple. Too much y cabling can and undoubtedly will lead to signal degradation.Note that in America this is pronounced "why-cable", and in Europe this is pronounced "ipsilon-cable."
Z - The electronic symbol for impedance-- frequency-dependent resistance, measured in Ohms.
Zero Reference - In sound land, it is a reference point that is defined as the average operating level for the equipment involved. Note that the term does not refer to the absence of signal, but instead serves as a method by which different pieces of equipment and source signals can be calibrated so that the average levels are consistent in order to provide for maximum signal-to-noise ratio and overall system gain. In the days of analog magnetic tape recording, machines were calibrated such that its VU (volume unit) meters would read 0 VU when given a reference tone, and the same principles apply to digital recording- often times the zero reference on a digital machine may be -12 or -16 on its digital scale.
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Comments, Questions, and Additions should be addressed via e-mail to Kai Harada. Not responsible for typographical errors.
http://www.harada-sound.com/sound/handbook/defs-z.html - © 2002 Kai Harada. 02.10.2002.