chebyshev ripple db (<0.0)
qfactor (resonator) (>0.0)
frequency Alpha Low Alpha Up or

samplerate: Hz
Lower corner Hz Midi note (69=A440)
Upper corner Hz Midi note (69=A440)
more matched z-transform (better off, check frequency response)
prewarp (better on)
Signal bits (including sign): -1 bit saturation save
brutal shift, this will remove shifts up to 4 positions by changing the factor, hence reducing accuracy by maximum 4 bits but more efficient calculation

//Low pass butterworth filter order=1 alpha1=0.1 class FilterBuLp1 { public: FilterBuLp1() { v[0]=v[1]=0.0; } private: float v[2]; public: float step(float x) //class II { v[0] = v[1]; v[1] = (2.452372752527856026e-1 * x) + (0.50952544949442879485 * v[0]); return (v[0] + v[1]); } };