With the setup of speaker, water tray and directional light (amp and oscillator out of shot.) What I'm doing here is trying to move the waves around manually.
Example one: A low frequency resonance (note large bandwidth). The metal tray has many resonant nodes, the complicated formation is due to the waves reflecting off the edges and corners. It would be interesting to see a more pure representation of a single spherical formation - though this is proving difficult to acheive.
Example 2: A much more elaborate formation at a higher frequency with a shallower amount of water. A blue bulb was being used at the stage.