Visualisation of Audio Effects Example 2
Illustrates the use of the Audio Phase-Space Scope for plotting the real-time trajectory of one audio signal versus another.
In this example, a triangular wave (produced by the Combo Wave Generator) is passed through a Moorer Comb filter (a key
element of IIR-based reverbs) and plotted against a delayed version of itself.The interesting thing to note is how the shape
of the plot (in the Audio Phase-Space Scope) changes when the harmonic order of the triangular wave is successively
increased (via the "Harmonics" slider in the Parameter Window of the Combo Wave Generator).
Play the DrawingBoard with its default settings. In the scope window you will see the elliptical form associated with the first
order (i.e. single harmonic) triangular wave passing through the comb. Note that the first order triangular wave is simply a
sine wave (as seen in the plot window of the Combo Wave Generator), and this is why the plot is an ellipse. Now increase
the harmonic order of the triangular wave by 1. After an initial transient, the scope will reveal a slight "kink" deformation with
respect to the simple ellipse. Now increase the order by 1 more.The scope will reveal yet another kink, and so forth as the
harmonic order is increased. This example reveals an interesting pattern whereby the harmonic order of the triangular wave
corresponds directly to the "kink" order of the "phase-space" plot.
Experiment with different effects other than the Moorer Comb. You will find the visualisations interesting (and sometimes
inspiring !).
