Example image of eyePlorer eyePlorer map for 'Butterworth filter': Filter (signal processing) Frequency response Passband Engineer Stephen Butterworth United Kingdom Ripple (electrical) Bode plot Decade Decibel Octave Chebyshev filter Elliptic filter Roll-off Stopband Low-pass filter Electrical impedance Group delay and phase delay Phase (waves) Transfer function High-pass filter Band-pass filter Band-stop filter Prototype filter Cutoff frequency Monotonic function Electronic filter topology Operational amplifier Sallen–Key topology RC circuit Bilinear transform Z-transform Digital biquad filter Network synthesis filters Optimum "L" filter Center frequency Linkwitz-Riley filter State variable topology Seismic Handler Infinite impulse response Noise shaping Impulse invariance Linear filter Phase margin Butterworth Active filter Audio crossover Q factor Targeted reinnervation Wilhelm Cauer