Smoothing calculates the mean of frequency values over a sliding frequency band. The band is usually Octave (e.g. one-third octave wide) to give an equal distribution along a logarithmic frequency axis.
A Constant band may also be used and may be useful e.g. if a linear frequency axis is used to display the data.
The last setting Constant@low freq. – Octave@high freq
does Constant bandwidth smoothing at low frequencies. But from the
frequency Octave
smoothing will be used.
