We need a processing plugin in which we can draw a curve on a frequency plot and have the plugin pan the input source according to frequency. For example lower frequencies would be panned center and high frequencies would be panned to the sides of the stereo image. The curve dictates the progressive widening or narrowing of the input as it is analyzed according the frequency. So it is not the entire source that is panned all narrow or all wide according to amplitude but rather the source is broken up into frequency granules and panned at the width specified for each granule so every source could have maximum stereo width but only the parts of the frequency spectrum that are drawn on the curve to be that wide.
Heya mate,
Melda Productions make a free plugin that does exactly this.