xoxos has released Mass and Cymbal - two percussion synthesizer VST instruments for Windows that use mass-spring models to produce realistic dynamic and timbral effects. Boundary conditions imposed upon the movement of a multi-order mass-spring provide complex timbres that evoke common modes of vibration in acoustic forms. These models are augmented with conventional subtractive elements to comprise low-CPU solutions for improved realtime percussion synthesis.

Mass and Cymbal are available as a bundle for $15.