In normal effects, panning is a pretty boring
effect. Pan to the left, pan to the right -- that's about the extent
of it.
Spectral panning, on the other hand, is an entirely different story. With Spectron you can grab regions of frequencies, pan them, modulate them, or envelope trigger them. You could, for example, have a drum loop where the high frequencies (and only the high frequencies) spread out to the sides each time the snare is hit. Or any number of other infinite possibilties.
Operation of the Pan module in Spectron is pretty straightforward. Select a node, and drag up to drag those frequencies to the left, or drag down to pan them to the right. In the screenshot below, for example, a single node is being used to pan the middle frequencies to the left.
Pan Tips:
1) Modulation, especially advanced modulation, can create very interesting spectral effects. Panning in general is usually very predictable, but spectral panning can give tracks movement without giving away exactly how it's being done.
2) The obvious modulation is to pan a node from left to right. Try modulating a pan over a range of frequencies instead. Start with the high frequencies panned slightly left, for example, then have that node slide down to pan middle frequencies slightly left.
3) For very strange spatial effects, experiment with spectral panning with the "Harmonics Only" and "Mute Unprocessed" frequencies options. This will effectively mute all of your audio expect harmonics, which can then be panned and swept across the frequency range and stereo field. If that effect by itself is too strange for you, try using Spectron as a send effect in your host app to control mix of dry (unpanned) and wet (panned harmonic frequencies)
4) Another send effect trick is to patch Spectron as a send effect and use the Pan and Delay modules to create delayed/panned spectral effects. The host app send/return control allows you to control the dry (not delayed) with the wet (spectrally delayed and panned)
5) Panning effects only apply to stereo files. If you're using a mono track, convert it to stereo in your host app before applying spectral panning effects.