# F0 (harmonic grid) method

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This method uses a harmonic grid algorithm to detect the fundamental frequency of a harmonic tone (or a mixture of tones) in the FFT amplitude spectrum. A simple tracking algorithm is applied to the resulting values of consecutive frames. The result is the parameter function `F0H`

(t) which can be stored in the DataSet.

- min/max
- Define the analysis and display fundamental frequency range in Hz.
- ref
- This is the reference frequency for Cent conversions.
- Hz
- Select the frequency unit for the display.
- f1, f2
- Define the frequency search component search range in Hz. This range can be outside the fundamental frequency range defined above.
- harmonics
- This is the minimum number of harmonic components building a harmonic tone. The value must be greater than or equal to
`1`

. - threshold
- Selects how the amplitude threshold for the component detection algorithm is computed. When a linear function threshold is specified, a linear function between the points (f1,a1) and (f2,a2) is computed and only peaks with amplitudes above this line are detected. For the threshold type cepstrum-smoothed spectrum, only peaks with amplitudes above the smoothed spectrum + offset are detected. The smoothed spectrum is an adaptive threshold and is very efficient for signals with a high dynamic range.
- a1,a2
- The threshold amplitudes for the threshold type linear function.
- rel. to spg-maximum
- The amplitude values are calculated relative to the spectrogram's maximum amplitude.
- coefs
- Number of coefficients for cepstrum smoothing.
- offset
- Amplitude offset for peak detection if the threshold is set to cepstrum-smoothed spectrum.