Conversion of distortion attenuation ak as damping in decibel (dB)
to distortion factor k (THD) as percent value %
|Fill out the gray box and click at the respective calculation bar under it.
Don't forget to enter the minus sign for the distortion attenuation in decibels.
|The distortion factor is always less than 1 or less than 100%, therefore, the total harmonic distortion
must always be a negative dB value. Total harmonic distortion: in dB.
Input k in percent. Total harmonic distortion (THD) in %. Input ak in dB with a
minus sign. To calculate the distortion factor, there are two different formulas:
= Distortion att. up to 5% × 100 = THD
The distortion factor was historically introduced before the THD-value and the ratio of the effective value of all harmonics to the RMS value of all harmonics plus fundamental frequency, that is the total signal.
The THD is the ratio of RMS signal of all harmonics to the RMS of the fundamental signal.
Asking for "THD expressed as a power ratio" is nonsense.
It is also common to specify the THD + N, where N stands for noise.
This test measures everything added to the input signal. Great, since everything that comes out of the unit that isn't the pure test signal is measured and included − harmonics, hum, noise, RFI, buzz ... everything.
|The distortion factor is always smaller than 1 or less than 100 %, therefore the
distortion attenuation must be a negative dB value.
Distortion attenuation: in dB. Input k in percent.
Distortion factor THD: in %. Input ak in dB with a minus sign.
Distortions and the dB calculation
Distortions as voltage or sound pressure belongs to the field quantities
|k||k (%)||ak (dB)|
where V2 to Vx are the amplitudes of harmonics to the fundamental amplitude V1.
Conversion of distortion factor k as percent value %
to distortion attenuation ak as damping in decibel (dB)
|Simply enter the value to the left or the right side.
The calculator works in both directions of the ↔ sign.
The distortion attenuation in dB must begin with a minus sign.
Don't forget the minus sign, when entering the distortion attenuation in decibels.
The scales of VU meters show decibel values and percentage values.
Addition of harmonic distortion attenuation of multiple devices.
|Overtones, partials and harmonics from fundamental frequency
Keyboard, frequencies = Naming of musical notes, piano keys
Frequency domain of musical instruments and voices