Total Harmonic Distortion. A term refering to how much distortion is introduced by a device at a given level. Used for rating the noise level of devices.
When a single frequency of specified level is applied to the input of a system, the ratio (of the voltage of the fundamental frequency to the voltage of all harmonics) observed at the output of the system because of the nonlinearities of the system; THD is expressed in percent.
Total harmonic distortion. this term has come into common usage to define either voltage or current "distortion factor."
Total Harmonic Distortion. A measure of the distortion content of a signal as represented by equivalent harmonics of that signal and specified as a percentage of the signal amplitude. While the equivalent harmonics represented do not actually exist in the signal, their summation would reproduce the distortion component of the signal. Further, filter separation of the signal into its fundamental and harmonic frequencies yields the harmonics for identification and measurement comparison with the fundamental.
TOTAL HARMONIC DISTORTION. A measure of the distortion of the sine wave on alternating current (ac) systems caused by higher order waves superimposed on the fundamental (usually 60hz) frequency of the system. Thd is expressed in percent and may refer to individual electrical loads (such as a ballast) or a total electrical circuit or system in a building. The ansi recommendation is for thd to be no greater than 32% although some electrical utilities may require lower thd's on some systems. Excessive thd's on electrical systems can cause efficiency losses as well as overheating and deterioration of system components.
The abbreviation for Total Harmonic Distortion. See also Harmonic Distortion Three Way Speaker - A speaker system design which features three separate drivers to reproduce the bass, midrange and high frequencies.
An abbreviation for Total Harmonic Distortion.
Total Harmonic Distortion. The sum of all harmonic distortions
Total harmonic distortion. A measure of the degree to which a sinusoidal wave shape is distorted by harmonic wave forms, with higher values of THD indicating greater distortion. Electrical devices, such as computers and fluorescent lighting systems, can send harmonic wave forms at many frequencies back onto the power supply line, thereby distorting the current wave shape. For 4-foot lamps, the American National Standards Institute (ANSI) recommends a THD limit of 32 percent, but some electric utilities only provide financial incentives for ballasts that produce less than 20 percent THD. Ballasts that produce less than 10 percent THD are available for installations with critical power requirements.
Total Harmonic Distortion. A specification, expressed in percentages, helpful in analyzing the performance of amplifiers and other processing gear.
Total harmonic distortion. Audio signals become distortion as they pass through electronic circuits. The amount of distortion is expressed as a percentage. Lower numbers are better, but in general the human ear cannot detect distortion less than 2%. Three-Way Speaker - A loudspeaker that has three drivers; one each for high frequencies, midrange, and bass.
Total harmonic distortion. Excessive THD (defined by ANSI as greater than 32%) may cause adverse effects to the electrical system. THD levels below 20% provide optimal system compatibility, but levels below 10% may not add any practical benefit. 10% THD types may also introduce excessive in-rush current unless circuitry is added that limits in-rush levels.
Total Harmonic Distortion. A measure of the distortion of the input current on alternating current (AC) power systems caused by higher order harmonics of the fundamental frequency (60Hz in North America). THD is expressed in percent and may refer to individual electrical loads (such as ballast) or a total electrical circuit or system in a building. ANSI C82.77 recommends THD not exceed 32% for individual commercial electronic ballasts, although some electrical utilities may require lower THDs on some systems. Excessive THDs on electrical systems can cause efficiency losses as well as overheating and deterioration of system componenets.
Total Harmonic Distortion. The ratio of the rms sum of the first six harmonic components to the rms value of the measured fundamental. It is expressed as a percentage or in decibels (dB).
Total harmonic distortion. A measurement of the total of all the harmonics introduced by nonlinear (uneven levels of) distortion in a device. This measurement is indicated as a percentage of the strength of the fundamental (lowest level).
Acronym for Total Harmonic Distortion.
Total Harmonic Distortion. The percentage of the total sound that is unintentionally created harmonics from the original signal. . When comparing audio components, the lower the number, the better.
Total Harmonic Distortion. the percentage, in relation to a pure input signal, of harmonically derived frequencies introduced in the sound reproducing circuitry and hi-fi equipment (including speakers).
Total Harmonic Distortion. THD measures the distortion content of a signal, and is specified in decibels relative to the carrier (dBc). For ADCs, THD is the ratio of the RMS sum of the selected harmonics of the input signal to the fundamental itself. Only harmonics within the Nyquist limit are included in the measurement.
Total Harmonic Distortion. The ratio of the total signal generated by harmonic distortion to the overall signal, expressed in dB or percent.
The percentage of an audio output signal that consists of spurious harmonic, or multiples of the fundamental frequencies. These harmonics are introduced by a power amplifier or other components through which the signal passes; lower figures are better.
See Total harmonic distortion
Total Harmonic Distortion. The ratio of the root-mean- square of the harmonic content to the root-mean-square value of the fundamental quantity, expressed as a percent of the fundamental. Typically a supply sine wave is considered acceptable when THD levels are 5% or less. See harmonics, harmonic distortion and distortion.
Total Harmonic Distortion. Describes how much the circuit voltage deviates from a perfect sine wave. A poor voltage THD is most often manifested in a “flat topped †waveform that comes from the inability of a power source to respond to the demands of highly non-linear loads.
Total harmonic distortion. Refers to a device adding harmonics that were not in the original signal. For example: a device that is fed a 20Hz sine wave that is also putting out 40Hz, 80Hz etc. Not usually a factor in most modern electronics, but still a significant design problem in loudspeakers.
abbreviation for "total harmonic distortion," a condition where a circuit adds additional unwanted harmonics (e.g., second and third harmonics) that were not part of the original signal. THD represents the effect of all the harmonic components (hence, the "total" part of the name, as opposed to second- or fifth-harmonic distortion) and is usually expressed as a percentage of the signal.
Distortion derived from the creation of harmonics (multiples of a base frequency signal) in an audio system adding additional frequency peaks to the output.
Total Harmonic Distortion. The amount of internally generated noise in a receiver that varies from the ideal sound wave. Since the perfect audio wave is physically impossible, the variation from the ideal wave is the percentage referred to as THD.
(total harmonic distortion) - A measure of all of the spurious signals added by a sound-reproducing device.
Total Harmonic Distortion. How much of the signal coming from the speaker cone is distorted. The lower the THD, the better the overall sound. A THD of 1% in the frequency range of 100 Hz - 2 kHz is imperceptible: below 100 Hz the perceptibility threshold lies at 10%.
Total Harmonic Distortion. THD is a measure of the degree to which a sinusoidal wave shape is distorted by harmonics. Fluorescent lamps operated with either magnetic or electronic ballasts reflect harmonics back into the electrical supply system and may range from 12-20% for magnetic ballasts and 5-30% for electronic ballasts. ANSI has recommended a limit of 32%.
Total Harmonic Distortion. the sum of all amplifier distortion components, plus system noise. THD measurements are sometimes quoted as THD+noise. Usually measured at specified frequencies and power levels
Total harmonic distortion. An audio measurement specification used to determine the accuracy with which a device can reproduce an input signal at its output. THD describes the cumulative level of the harmonic overtones that the device being tested adds to an input sine wave. THD+n is a specification that includes both harmonic distortion of the sine wave and nonharmonic noise.
Total Harmonic Distortion. The amount of undesirable harmonics present in an output audio signal expressed as a precentage. The lower the percentage the better.
Total Harmonic Distortion. The square root of the sum of the squares of the RMS harmonic voltages or currents divided by the RMS fundamental voltage or current. Typically a supply sine wave is considered acceptable when THD levels are 5% or less. See harmonics, harmonic distortion and distortion. Can also be calculated in the same way for only even harmonics or odd harmonics.
Total harmonic distortion. The ratio of the total rms signal due to harmonic distortion to the overall rms signal, in dB or percent.
Total Harmonic Distortion. The noise referenced to signal in decibels (dB) as a percentage.