Whistle 2 is a physical modelling synthesizer with a banded waveguide as a resonator, disturbed with a granulated noise exciter source.

Banded waveguide synthesis is a physical modeling synthesis method that can be used to model elastic solids, like a vibraphone or a marimba. The synthesis method propagates exciter disturbances across tuned frequency bands. In whistle the amplitude and the partials of these frequency bands can be dialed in and automated.

The exciter of Whistle uses a granular engine to process the noise source. This design creates a uniquely unpredictable texture, with any tonal elements in the exciter source interacting with the resonator to create random harmonic content.