Octave Band Pole Calculator
Calculate analog Butterworth bandpass poles for octave and third-octave bands using standard center frequencies.
Info topics
How bandpass poles are formed
Start with low-pass Butterworth prototype poles in the left half-plane. Apply the bandpass transform
s -> (s^2 + w0^2) / (B s) where w0 = sqrt(w1 * w2) and B = w2 - w1.
Each prototype pole produces two bandpass poles.
Choose the band type first, then a standard center frequency to see the resulting analog poles.
Pole calculator (analog)
Poles are shown in rad/s. Digital pole locations depend on the bilinear transform and sample rate.