Total harmonic distortion, the Glossary
The total harmonic distortion (THD or THDi) is a measurement of the harmonic distortion present in a signal and is defined as the ratio of the sum of the powers of all harmonic components to the power of the fundamental frequency.[1]
Table of Contents
34 relations: A-weighting, Amplitude, Analog Devices, Audio system measurements, Auditory masking, Band-stop filter, Bandwidth (signal processing), Butterworth filter, Computer, Cutoff frequency, Decibel, Distortion, Duty cycle, Fourier analysis, Fundamental frequency, Ground loop (electricity), Harmonic, Intermodulation, International Electrotechnical Commission, ITU-R 468 noise weighting, Linear time-invariant system, Percentage, Pulse wave, Sawtooth wave, Signal-to-noise ratio, SINAD, Sine wave, Sound card, Square wave, Timbre, Total harmonic distortion analyzer, Transfer function, Triangle wave, Waveform.
- Audio amplifier specifications
A-weighting
A-weighting is a form of frequency weighting and the most commonly used of a family of curves defined in the International standard IEC 61672:2003 and various national standards relating to the measurement of sound pressure level.
See Total harmonic distortion and A-weighting
Amplitude
The amplitude of a periodic variable is a measure of its change in a single period (such as time or spatial period).
See Total harmonic distortion and Amplitude
Analog Devices
Analog Devices, Inc. (ADI), also known simply as Analog, is an American multinational semiconductor company specializing in data conversion, signal processing, and power management technology, headquartered in Wilmington, Massachusetts.
See Total harmonic distortion and Analog Devices
Audio system measurements
Audio system measurements are a means of quantifying system performance. Total harmonic distortion and Audio system measurements are audio amplifier specifications.
See Total harmonic distortion and Audio system measurements
Auditory masking
In audio signal processing, auditory masking occurs when the perception of one sound is affected by the presence of another sound.
See Total harmonic distortion and Auditory masking
Band-stop filter
In signal processing, a band-stop filter or band-rejection filter is a filter that passes most frequencies unaltered, but attenuates those in a specific range to very low levels.
See Total harmonic distortion and Band-stop filter
Bandwidth (signal processing)
Bandwidth is the difference between the upper and lower frequencies in a continuous band of frequencies.
See Total harmonic distortion and Bandwidth (signal processing)
Butterworth filter
The Butterworth filter is a type of signal processing filter designed to have a frequency response that is as flat as possible in the passband.
See Total harmonic distortion and Butterworth filter
Computer
A computer is a machine that can be programmed to automatically carry out sequences of arithmetic or logical operations (computation).
See Total harmonic distortion and Computer
Cutoff frequency
In physics and electrical engineering, a cutoff frequency, corner frequency, or break frequency is a boundary in a system's frequency response at which energy flowing through the system begins to be reduced (attenuated or reflected) rather than passing through.
See Total harmonic distortion and Cutoff frequency
Decibel
The decibel (symbol: dB) is a relative unit of measurement equal to one tenth of a bel (B).
See Total harmonic distortion and Decibel
Distortion
In signal processing, distortion is the alteration of the original shape (or other characteristic) of a signal. Total harmonic distortion and distortion are audio amplifier specifications.
See Total harmonic distortion and Distortion
Duty cycle
A duty cycle or power cycle is the fraction of one period in which a signal or system is active.
See Total harmonic distortion and Duty cycle
Fourier analysis
In mathematics, Fourier analysis is the study of the way general functions may be represented or approximated by sums of simpler trigonometric functions.
See Total harmonic distortion and Fourier analysis
Fundamental frequency
The fundamental frequency, often referred to simply as the fundamental, is defined as the lowest frequency of a periodic waveform.
See Total harmonic distortion and Fundamental frequency
Ground loop (electricity)
In an electrical system, a ground loop or earth loop occurs when two points of a circuit are intended to have the same ground reference potential but instead have a different potential between them.
See Total harmonic distortion and Ground loop (electricity)
Harmonic
In physics, acoustics, and telecommunications, a harmonic is a sinusoidal wave with a frequency that is a positive integer multiple of the fundamental frequency of a periodic signal.
See Total harmonic distortion and Harmonic
Intermodulation
Intermodulation (IM) or intermodulation distortion (IMD) is the amplitude modulation of signals containing two or more different frequencies, caused by nonlinearities or time variance in a system. Total harmonic distortion and intermodulation are audio amplifier specifications.
See Total harmonic distortion and Intermodulation
International Electrotechnical Commission
The International Electrotechnical Commission (IEC; Commission électrotechnique internationale) is an international standards organization that prepares and publishes international standards for all electrical, electronic and related technologies – collectively known as "electrotechnology".
See Total harmonic distortion and International Electrotechnical Commission
ITU-R 468 noise weighting
ITU-R 468 (originally defined in CCIR recommendation 468-4, therefore formerly also known as CCIR weighting; sometimes referred to as CCIR-1k) is a standard relating to noise measurement, widely used when measuring noise in audio systems.
See Total harmonic distortion and ITU-R 468 noise weighting
Linear time-invariant system
In system analysis, among other fields of study, a linear time-invariant (LTI) system is a system that produces an output signal from any input signal subject to the constraints of linearity and time-invariance; these terms are briefly defined in the overview below.
See Total harmonic distortion and Linear time-invariant system
Percentage
In mathematics, a percentage is a number or ratio expressed as a fraction of 100.
See Total harmonic distortion and Percentage
Pulse wave
A pulse wave or pulse train or rectangular wave is a non-sinusoidal waveform that is the periodic version of the rectangular function.
See Total harmonic distortion and Pulse wave
Sawtooth wave
The sawtooth wave (or saw wave) is a kind of non-sinusoidal waveform.
See Total harmonic distortion and Sawtooth wave
Signal-to-noise ratio
Signal-to-noise ratio (SNR or S/N) is a measure used in science and engineering that compares the level of a desired signal to the level of background noise. Total harmonic distortion and signal-to-noise ratio are audio amplifier specifications and electrical parameters.
See Total harmonic distortion and Signal-to-noise ratio
SINAD
The signal-to-noise and distortion ratio (SINAD) is a measure of the quality of a signal from a communications device, often defined as \mathrm.
See Total harmonic distortion and SINAD
Sine wave
A sine wave, sinusoidal wave, or sinusoid (symbol: ∿) is a periodic wave whose waveform (shape) is the trigonometric sine function.
See Total harmonic distortion and Sine wave
Sound card
A sound card (also known as an audio card) is an internal expansion card that provides input and output of audio signals to and from a computer under the control of computer programs.
See Total harmonic distortion and Sound card
Square wave
A square wave is a non-sinusoidal periodic waveform in which the amplitude alternates at a steady frequency between fixed minimum and maximum values, with the same duration at minimum and maximum.
See Total harmonic distortion and Square wave
Timbre
In music, timbre, also known as tone color or tone quality (from psychoacoustics), is the perceived sound quality of a musical note, sound or tone.
See Total harmonic distortion and Timbre
Total harmonic distortion analyzer
A total harmonic distortion analyzer calculates the total harmonic content of a sinewave with some distortion, expressed as total harmonic distortion (THD).
See Total harmonic distortion and Total harmonic distortion analyzer
Transfer function
In engineering, a transfer function (also known as system function or network function) of a system, sub-system, or component is a mathematical function that models the system's output for each possible input.
See Total harmonic distortion and Transfer function
Triangle wave
A triangular wave or triangle wave is a non-sinusoidal waveform named for its triangular shape.
See Total harmonic distortion and Triangle wave
Waveform
In electronics, acoustics, and related fields, the waveform of a signal is the shape of its graph as a function of time, independent of its time and magnitude scales and of any displacement in time.
See Total harmonic distortion and Waveform
See also
Audio amplifier specifications
- Audio power
- Audio system measurements
- Crossover distortion
- Crosstalk
- Damping factor
- Distortion
- Dynamic range
- Frequency response
- Input impedance
- Intermodulation
- Nominal impedance
- Output impedance
- Phase distortion
- Power bandwidth
- Power gain
- Signal-to-noise ratio
- Total harmonic distortion
References
[1] https://en.wikipedia.org/wiki/Total_harmonic_distortion
Also known as THD+N, THDi, Total harmonic distortion plus noise.