Signal Processing & DSP

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Total Harmonic Distortion

Ratio of harmonic energy to the fundamental.

Formula

THD = \frac{\sqrt{\sum_{n\ge2} V_n^2}}{V_1}

Variables

THDDistortion ratio

V_1Fundamental amplitude

V_nn-th harmonic amplitude

Example

Hi-fi amps aim for THD well below 0.1%.

Did You Know?

A guitar amp's warm 'crunch' is deliberately high THD — distortion that musicians prize rather than avoid.

dsp thd distortion

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