Box Model Applet (resonance in cubical box simulator)

For a demo (and a great lecture) see:

Steven Lehar | Harmonic Gestalt: Sound from Structure: A holistic Invariant Representation of Spatial Structure through Sound as a model of perception (Qualia Research Institute) - https://www.youtube.com/watch?v=LJiXTCbFtu0 (around 35min in)