A command to modify every selected Spectrum object.
The complex values in the Spectrum are multiplied by real-valued sine shapes and straight lines, according to the following figure:
This filter is the complement from the pass-band filter (Spectrum: Filter (pass Hann band)...). For instance, we can decompose the spectrum into the above stop-band spectrum and a band from 500 to 1000 Hz:
By adding the two spectra together, we get the original spectrum again.
See the Filtering tutorial for information on the need for smoothing and a comparative discussion of various filters.
© ppgb, September 16, 2003