Block size defines the calculation interval. The resulting frequency will be updated with this speed, but we need to take care that this interval will be longer than 10 measured periods of the signal.
Amplitude threshold defines the minimum amplitude where the signal is still calculated. If the RMS of the signal is below this limit, the frequency will not be calculated at
By default, the Exact frequency math will search for the highest harmonic in the whole frequency range. You can manually select the freqeuncy range in which the program should search for the highest harmonic. In this case, the freqeuncy will be found in defined freqency range.