Spectral Selection
Spectral selection is used to make selections that include a frequency range as well as a time range.
Tracks must be in one of the spectrogram views in order to use spectral selection.
Spectral selection is used with special "Spectral edit" effects to make changes to the frequency content of the selected audio.
Making a Spectral Selection
Here is a track with a few seconds of speech, shown in waveform view.
When you change the track to spectrogram view you can draw a "box" that defines both a frequency range and a time range as shown below.
The combined frequency/time range is indicated by the darker-shaded box.
A spectral selection may begin or end either at 0 Hz or at the maximum allowable frequency for the track (the Nyquist frequency), in which case no center frequency will be shown. In the illustration below the frequency selection goes from 0 Hz to about 4000 Hz.
- Bill 19Oct2014: Do we need an illustration of a selection up to the Nyquist frequency? That would entail also describing zooming in spectrogram view which might be useful (but that properly belongs in Zooming I suppose.
Adjusting a Spectral Selection
When you hover the cursor over the center frequency line it changes to indicate that the centre frequency can be dragged. Click and drag to move the centre frequency to a new position as shown below.
Hover the cursor over the upper frequency boundary or the lower frequency boundary then click and drag to adjust those boundaries.
Hold down the ALT key then click and drag to adjust the upper and lower frequency boundaries simultaneously keeping them equally spaced around the center frequency (and thus not changing the centre frequency).
Hold down the ALT key then tap the CTRL key to move the center frequency and have it snap to frequency peaks. Note that you do not have to click and drag. Once the center frequency has snapped to where you want it you can then click and drag (while still holding down the ALT key) to adjust the upper and lower frequency boundaries.
