Frequency response shapes for loudspeakers 
Means for obtaining high-pass filter functions using (1) Bessel polynomials, (2) Butterworth polynomials, and (3) Chebyshev polynomials are covered in this appendix.
Keywords: Bessel polynomials; Butterworth polynomials; Chebyshev polynomials; Frequency; High-pass filter; Ripple factor.
In the following high-pass filter functions G
), the order of the function is denoted by N
and the frequency at which the magnitude of the response is
(that is, 3
dB below the pass band level) is denoted by ω