I’m picking my way through Real Sound Synthesis for Interactive Applications by Perry R. Cook (one of the authors of the STK) and decided to start making small apps to demonstrate the different kinds of synthesis he covers in the book. This first one let’s you set the variables of a mass-spring-damper system and then trigger it, which is exactly the same as setting the coefficients of a two-pole IIR filter and sending an impulse into it (as it turns out). Check it: