2WarpDelay

2WarpDelay pairs two warped-lattice IIR filters with a pair of delay lines and a bitmap which it scans to extract filter coefficients.

A stereo signal is fed through two delay lines followed by a warped IIR lattice filter. The lattice filter can be of any order from 1 to 80 and uses reflection coefficients extracted from an image. This output is fed through a saturation stage and a ducking / limiting stage before being fed back, again, into the delay lines. The lattice filter is warped, and by adjusting the warping parameter its frequency response can be easily adjusted.

Resonance controls the distance between spectral peaks and spectral valleys in the filter transfer function, and cutoff controls the cutoff of a first-order low pass filter that follows the lattice filter.