SpectralPhaser is an effect that produces a phaser-like sound by applying a mask in the frequency domain. In addition to FFT, fast Walsh-Hadamard transform (FWHT) and Haar transform are available.
Discrete Fourier transform turns the input signal into a series of sine and cosine. Similarly, FWHT and Haar transform turn the signal into a series of square waves, which tend to sound rough to the human ear.
The drum membrane texture of mymembrane~ comes from a schroeder allpass placed on the feedback path of a comb filter. It's pretty fun to change the allpass parameters to add some expressions. Snare wire is a bandpassed noise following the amplitude of comb filter output, which is simple but sounds good.
RoughlySnare puts the cascade of (delay) -> (allpass) -> (snare wire) into a feedback delay network (FDN). There's also a second FDN to add tones. Delay times are set according to preferred modes of timpani.
DoubleLoopCymbal is a synthesizer that produces a sound somewhere between hi-hat and triangle. Metallic texture comes from 2 all-pass loops.
Block diagram is available on the manual page.
It is making some metallic noise, however it sounds synthetic when listening closer. Different tunings are tried, but I couldn't manage to add a better closing texture, and the crash texture which appears on a real cymbal when hit hard. It seems like closing of hi-hat can't be made from allpass loops. To stop sound, the feeds of allpasses should be moved to 0. However changing the feeds adds a texture similar to a phaser. On the crash texture, I found a better method described by henry bracey (link, description is on a comment). This method is not implement in this time since I wanted to make DoubleLoopCymbal lighter than ClangCymbal.
