3 Jan
2002
3 Jan
'02
5:16 a.m.
Hello, biquad~ formula in the PD help-patch is : y(n) = ff1 * w(n) + ff2 * w(n-1) + ff3 * w(n-2) w(n) = x(n) + fb1 * w(n-1) + fb2 * w(n-2)
biquad~ formula in Jmax is : y[n] = c1*x[n] + c2*x[n-1] + c3*x[n-2] - c4*y[n-1] - c5*y[n-2]
What is the mathematical relation between these two formulae (so between Pd and Jmax coefficients) ?
I found a nice document that explains how to get the right coeffs for different filters : http://www.harmony-central.com/Computer/Programming/Audio-EQ-Cookbook.txt and I'm not sure how to use it with PD biquad~ object.
nicolas