A distortion is the alteration of the original shape (or other characteristic) of an object, image, sound, waveform or other form of information or representation. Distortion is usually unwanted. In some fields, distortion is desirable, such as electric guitar (where distortion is often induced purposely with the amplifier to achieve the electric guitar's desired, electrifying, aggressive sound). The slight distortion of analog tapes and vacuum tubes is considered pleasing in certain situations. The addition of noise or other extraneous signals (hum, interference) is not considered to be distortion, though the effects of distortion are sometimes considered noise. Look up distortion in Wiktionary, the free dictionary. ... An electric guitar is a type of guitar that uses pickups to convert the vibration of its steel-cored strings into electrical current, which is then amplified. ... An instrument amplifier is an electronic amplifier designed for use with an electric or electronic musical instrument, such as an electric guitar. ... Compact audio cassette Magnetic tape is a non-volatile storage medium consisting of a magnetic coating on a thin plastic strip. ... Structure of a vacuum tube diode Structure of a vacuum tube triode In electronics, a vacuum tube, electron tube, or (outside North America) thermionic valve or just valve, is a device used to amplify, switch or modify a signal by controlling the movement of electrons in an evacuated space. ... In science, and especially in physics and telecommunication, noise is fluctuations in and the addition of external factors to the stream of target information (signal) being received at a detector. ... Spectrum of mains hum at 60 Hz Electric hum, mains hum, or power line hum is an audible oscillation at the frequency of the mains alternating current, which is usually 50 or 60 hertz depending on the local electric utility configuration (see Mains electricity). ... Radio Frequency Interference (RFI) is electromagnetic radiation which is emitted by electrical circuits carrying rapidly changing signals, as a by-product of their normal operation, and which causes unwanted signals (interference or noise) to be induced in other circuits. ...

Electronic signals

Graph of a waveform and the distorted versions of the same waveform

In telecommunication and signal processing, a noise-free "system" can be characterised by a transfer function, such that the output y(t) can be written as a function of the input x as Image File history File links Distorted_waveforms_square_sine. ... Image File history File links Distorted_waveforms_square_sine. ... Copy of the original phone of Alexander Graham Bell at the Musée des Arts et Métiers in Paris Telecommunication is the transmission of signals over a distance for the purpose of communication. ... Signal processing is the processing, amplification and interpretation of signals, and deals with the analysis and manipulation of signals. ... For other uses, see System (disambiguation). ... A transfer function is a mathematical representation of the relation between the input and output of a linear time-invariant system. ...

y(t) = F(x(t))

When the transfer function comprises only a perfect gain constant A and perfect delay T In electronics, gain is usually taken as the mean ratio of the signal output of a system to the signal input of the system. ... In its general sense, delay refers to a lapse of time. ...

the output is undistorted. Distortion occurs when the transfer function F is more complicated than this. If F is a linear function, for instance a filter whose gain and/or delay varies with frequency, then the signal will experience linear distortion. Linear distortion will not change the shape of a single sinuosoid, but will usually change the shape of a multi-tone signal.

This diagram shows the behaviour of a signal (made up of a square wave followed by a sine wave) as it is passed through various distorting functions. A square wave is a kind of basic waveform. ... In trigonometry, an ideal sine wave is a waveform whose graph is identical to the generalized sine function y = Asin[ω(x − α)] + C, where A is the amplitude, ω is the angular frequency (2π/P where P is the wavelength), α is the phase shift, and C...

1. The first trace (in black) shows the input. It also shows the output from a non-distorting transfer function (straight line).
2. A high-pass filter (green trace) will distort the shape of a square wave by reducing its low frequency components. This is the cause of the "droop" seen on the top of the pulses. This "pulse distortion" can be very significant when a train of pulses must pass through an AC-coupled (high-pass filtered) amplifier. As the sine wave contains only one frequency, its shape is unaltered.
3. A low-pass filter (blue trace) will round the pulses by removing the high frequency components. All systems are low pass to some extent. Note that the phase of the sine wave is different for the lowpass and the highpass cases, due to the phase distortion of the filters.
4. A slightly non-linear transfer function (purple), this one is gently compressing as may be typical of a tube audio amplifier, will compress the peaks of the sine wave. This will cause small amounts of low order harmonics to be generated.
5. A hard-clipping transfer function (red) will generate high order harmonics. Parts of the transfer function are flat, which indicates that all information about the input signal has been lost in this region.

The transfer function of an ideal amplifier, with perfect gain and delay, is only an approximation. The true behavior of the system is usually different. Nonlinearities in the transfer function of an active device (such as vacuum tubes, transistors, and operational amplifiers) are a common source of non-linear distortion; in passive components (such as a coaxial cable or optical fiber), linear distortion can be caused by inhomogeneities, reflections, and so on in the propagation path. A high-pass filter is a filter that passes high frequencies well, but attenuates (or reduces) frequencies lower than the cutoff frequency. ... A low-pass filter is a filter that passes low frequencies but attenuates (or reduces) frequencies higher than the cutoff frequency. ... This article is about a portion of a periodic process. ... To do: 20th century mathematics chaos theory, fractals Lyapunov stability and non-linear control systems non-linear video editing See also: Aleksandr Mikhailovich Lyapunov Dynamical system External links http://www. ... The picture shows an oscilloscope screen of an amplifier clipping. ... To do: 20th century mathematics chaos theory, fractals Lyapunov stability and non-linear control systems non-linear video editing See also: Aleksandr Mikhailovich Lyapunov Dynamical system External links http://www. ... An electrical circuit consists of various components or devices or elements, which may be active or passive. ... Structure of a vacuum tube diode Structure of a vacuum tube triode In electronics, a vacuum tube, electron tube, or (outside North America) thermionic valve or just valve, is a device used to amplify, switch or modify a signal by controlling the movement of electrons in an evacuated space. ... Assorted discrete transistors A transistor is a semiconductor device, commonly used as an amplifier or an electrically controlled switch. ... A 741 operational amplifier in a TO-5 metal can package An operational amplifier, usually referred to as an op-amp for brevity, is a DC-coupled high-gain electronic voltage amplifier with Differential Inputs and, usually, a single output. ... Various components An electronic component is a basic electronic element usually packaged in a discrete form with two or more connecting leads or metallic pads. ... Coaxial Cable For the weapon, see coaxial weapon. ... Optical fibers An optical fiber (or fibre) is a glass or plastic fiber designed to guide light along its length by confining as much light as possible in a propagating form. ... Reflection in electricity is the result of impedance mismatch in electrical signals. ... Wave propagation refers to the ways waves travel through a medium (waveguide). ...

Amplitude distortion

Main article: Amplitude distortion

Amplitude distortion is distortion occurring in a system, subsystem, or device when the output amplitude is not a linear function of the input amplitude under specified conditions. Amplitude distortion: Distortion occurring in a system, subsystem, or device when the output amplitude is not a linear function of the input amplitude under specified conditions. ... For other uses, see System (disambiguation). ... // Information processing In information processing, output is the process of transmitting information by an object (verb usage). ... A linear function is a mathematical function term of the form: f(x) = m x + c where c is a constant. ... Input3 is the term denoting either an entrance or changes which are inserted into a system and which activate/modify a process. ...

Frequency distortion

This form of distortion occurs when different frequencies are amplified by different amounts, mainly caused by combination of active device and components. For example, the non-uniform frequency response curve of RC-coupled cascade amplifier is an example of frequency distortion. In electronics, an active component is one that has gain or depends on the direction of the current. ... A cascade amplifier has many of the same benefits as a cascode. ...

Phase distortion

Main article: Phase distortion

This form of distortion mostly occurs due to the reactive component, such as capacitive reactance or inductor capacitance. Here, all the components of the input signal are not amplified with the same phase shift, hence causing some parts of the output signal to be out of phase with the rest of the output. Phase distortion: Distortion that occurs when (a) the phase-frequency characteristic is not linear over the frequency range of interest, , the phase shift introduced by a circuit or device is not directly proportional to frequency, or (b) the zero-frequency intercept of the phase-frequency characteristic is not 0 or... In the analysis of an alternating-current electrical circuit (for example a RLC series circuit), reactance is the imaginary part of impedance, and is caused by the presence of inductors or capacitors in the circuit. ... An inductor is a passive electrical device employed in electrical circuits for its property of inductance. ... Capacitance is a measure of the amount of electric charge stored (or separated) for a given electric potential. ...

Group delay distortion

Can be found only in dispersive media. In a waveguide, propagation velocity varies with frequency. In a filter, group delay tends to peak near the cut-off frequency, resulting in pulse distortion Dispersion of a light beam in a prism. ... Look up waveguide in Wiktionary, the free dictionary. ... Wave velocity is a general concept, of various kinds of wave velocities, for an electromagnetic waves phase and speed concerning energy (and information) propagation. ... In telecommunications, the term cutoff frequency fc has the following meanings: 1. ...

Correction of distortion

As the system output is given by y(t) = F(x(t)), then if the inverse function F^-1 can be found, and used intentionally to distort either the input or the output of the system, then the distortion will be corrected.

An example of such correction is where LP/Vinyl recordings or FM audio transmissions are deliberately pre-emphasised by a linear filter, the reproducing system applies an inverse filter to make the overall system undistorted. Chemical structure of the vinyl functional group. ... FM broadcasting is a broadcast technology invented by Edwin Howard Armstrong that uses frequency modulation (FM) to provide high-fidelity sound over broadcast radio. ... A linear filter applies a linear operator to a time-varying input signal. ...

Correction is not possible if the inverse does not exist, for instance if the transfer function has flat spots (the inverse would map multiple input points to a single output point). This results in a loss of information, which is uncorrectable. Such a situation can occur when an amplifier is overdriven, resulting in clipping or slew rate distortion, when for a moment the output is determined by the characteristics of the amplifier alone, and not by the input signal. A transfer function is a mathematical representation of the relation between the input and output of a linear time-invariant system. ... Look up clipping in Wiktionary, the free dictionary. ... In electronics, the slew rate is a nonlinear effect in amplifiers. ...

Teletypewriter or modem signaling

In binary signaling such as FSK, distortion is the shifting of the significant instants of the signal pulses from their proper positions relative to the beginning of the start pulse. The magnitude of the distortion is expressed in percent of an ideal unit pulse length. This is sometimes called 'bias' distortion. In telecommunication, signalling (or signaling) has the following meanings: The use of signals for controlling communications. ... FSK can have alternative meanings; Frequency-shift keying is frequency modulation. ... ˌ For other uses, see Pulse (disambiguation). ... ˌ For other uses, see Pulse (disambiguation). ...

Audio distortion

A graph of a waveform and the distorted version of the same waveform

In this context, distortion refers to any kind of deformation of a waveform, compared to an input. Clipping, compression, non-linear behavior of electronic components, modulation, aliasing, and mixing phenomena or power supply inefficiencies can cause distortion. Image File history File links Download high resolution version (507x763, 13 KB) Summary This image was made by me using Praat by synthesizing a waveform using some sine functions and using arctan() function to distort it. ... Image File history File links Download high resolution version (507x763, 13 KB) Summary This image was made by me using Praat by synthesizing a waveform using some sine functions and using arctan() function to distort it. ... Clipping is one form of distortion that occurs when an amplifier is overdriven, which happens when it attempts to increase voltage or current beyond its limits. ... Audio level compression, also called dynamic range compression, volume compression, compression, limiting, or DRC (often seen in DVD player settings) is a process that manipulates the dynamic range of an audio signal. ... In telecommunications, modulation is the process of varying a periodic waveform, i. ... Properly sampled image of brick wall. ... Audio mixing is used in sound recording, audio editing and sound systems to balance the relative volume and frequency content of a number of sound sources. ...

Distorted waveforms Image File history File links Distortion_effect. ...

An audio example of a short sample followed by different distorted versions of it.

Problems listening to the file? See media help.

In most fields, distortion is characterized as unwanted change to a signal.

Gabber

Distortion is one of the most important elements of Gabber music. Usually Distortion filters is added on drum patterns and bassline to achieve a very hard and raw sound. Gabber (IPA pronunciation: ), gabba, or hardcore, is a style of electronic music and a subgenre of hardcore techno. ...

Main articles: Gabber, Hardcore_dance_music, Terrorcore, Speedcore, and Hardstyle

Gabber (IPA pronunciation: ), gabba, or hardcore, is a style of electronic music and a subgenre of hardcore techno. ... Hardcore (sometimes ardcore) is a term that has been used to describe a variety of related electronic dance music styles over almost two decades. ... This article does not cite any references or sources. ... Speedcore is a form of hardcore techno that is typically identified by its high rate of beats per minute and aggressive themes. ... Hardstyle, sometimes referred to as hardbass, is a sub-genre of trance music that is closely related to nu style gabber and hard trance. ...

Guitar sound

Distortion is an important part of an electric guitar's sound in many musical genres, including rock, hard rock, punk rock, garage punk and heavy metal. Typically, the signal coming from the guitar is distorted by a "clipping" of its waveform. This is commonly done with an effects pedal that is connected between the guitar and its amplifier. An electric guitar is a type of guitar that uses pickups to convert the vibration of its steel-cored strings into electrical current, which is then amplified. ... For other uses, see Rock music (disambiguation). ... “Hard Rock” redirects here. ... Punk rock is an anti-establishment music movement beginning around 1976 (although precursors can be found several years earlier), exemplified and popularised by The Ramones, the Sex Pistols, The Clash and The Damned. ... Garage punk is a subgenre of punk rock that is closely related to garage rock. ... “Heavy metal” redirects here. ... It has been suggested that this article or section be merged into Effects unit. ... For the British rock band of the same name, see Amplifier (band). ...

Main article: Guitar effects

Guitar effects are electronic devices that modify the tone, pitch, or sound of an electric guitar. ...

Optics

In optics, image distortion is a divergence from rectilinear projection caused by a change in magnification with increasing distance from the optical axis of an optical system. For the book by Sir Isaac Newton, see Opticks. ... Barrel distortion simulation Pincushion distortion simulation In geometric optics and cathode ray tube (CRT) displays, image distortion is a deviation from rectilinear projection, a projection in which straight lines in a scene remain straight in an image. ... In photography, a rectilinear lens is a photographic lens that yields images where straight features, such as the walls of buildings, appear with straight lines, as opposed to being curved. ... Magnification is the process of enlarging something only in appearance, not physical size. ... In telecommunication, the term optical axis has the following meanings: 1. ...

Map projections

In cartography, a distortion is a misrepresentation of the area or shape of a feature. The Mercator projection, for example, distorts Greenland because of its high latitude, in the sense that its shape and size are not the same as those on a globe. Cartography or mapmaking (in Greek chartis = map and graphein = write) is the study and practice of making maps or globes. ... Mercator world map Nova et Aucta Orbis Terrae Descriptio ad Usum Navigatium Emendate (1569) The Mercator projection is a cylindrical map projection presented by the Flemish geographer and cartographer Gerardus Mercator, in 1569. ... This article is about the geographical term. ... World globe A Baroque era celestial globe A globe is a three-dimensional scale model of a spheroid celestial body such as a planet, star or moon, in particular Earth, or, alternatively, a spherical representation of the sky with the stars (but without the Sun, Moon, or planets, because their...

See also

• Attenuation Distortion
• Total harmonic distortion — a measurement of the amount of distortion in a sinusoidal waveform
• Valve sound
• Distortion (guitar)

There are very few or no other articles that link to this one. ... The total harmonic distortion, or THD, of a signal is a measurement of the harmonic distortion present and is defined as the ratio of the sum of the powers of all harmonic components to the power of the fundamental. ... Valve sound is the sound either from a valve amplifier or a specially designed transistor amplifier. ... In the world of guitar music and guitar amplification, distortion is actively sought, evaluated, and appreciatively discussed in its endless flavors. ...

References

External links

• A Musical-Distortion Primer
• Distortion 101
• Multiband Distortion ensemble for Reaktor