Вот, например, полосовой Баттерворт 5-го порядка:
Filter kind:
1 Butterworth
2 Chebyshev
3 Elliptic
? 1
Filter shape:
1 low pass
2 band pass
3 high pass
4 band stop
? 2
Order of filter = 8.000000000E+000 ? 5.000000000E+000
Sampling frequency = 1.000000000E+004 ? 1.000000000E+005
Passband edge = 2.000000000E+003 ? 1.000000000E+002
Other passband edge = 1.500000000E+003 ? 1.000000000E+004
s plane poles:
-1.000000000E+000 0.000000000E+000
-8.090169944E-001 5.877852523E-001
-3.090169944E-001 9.510565163E-001
s plane zeros:
adding zero at Nyquist frequency
adding zero at 0 Hz
adding zero at Nyquist frequency
adding zero at 0 Hz
adding zero at Nyquist frequency
adding zero at 0 Hz
adding zero at Nyquist frequency
adding zero at 0 Hz
adding zero at Nyquist frequency
adding zero at 0 Hz
order = 10
constant gain factor 1.2287628361445E-003
z plane Denominator Numerator
0 1.000000000E+000 1.228762836E-003
1 -7.979208154E+000 0.000000000E+000
2 2.872239538E+001 -6.143814181E-003
3 -6.149319622E+001 0.000000000E+000
4 8.679787409E+001 1.228762836E-002
5 -8.445800019E+001 0.000000000E+000
6 5.739718446E+001 -1.228762836E-002
7 -2.690499761E+001 0.000000000E+000
8 8.325320215E+000 6.143814181E-003
9 -1.535545154E+000 0.000000000E+000
10 1.281731776E-001 -1.228762836E-003
poles and zeros with corresponding quadratic factors
pole 9.9361210463166E-001 0.0000000000000E+000
q. f.
z**2 0.0000000000000E+000
z**1 -9.9361210463166E-001
f0 5.00000000E+004 gain 5.0160E-001 DC gain 1.5655E+002
zero -1.0000000000000E+000 0.0000000000000E+000
q. f.
z**2 0.0000000000000E+000
z**1 1.0000000000000E+000
f0 5.00000000E+004 gain 0.0000E+000 DC gain 2.0000E+000
pole 5.1679020982377E-001 0.0000000000000E+000
q. f.
z**2 0.0000000000000E+000
z**1 -5.1679020982377E-001
f0 5.00000000E+004 gain 6.5929E-001 DC gain 2.0695E+000
zero 1.0000000000000E+000 0.0000000000000E+000
q. f.
z**2 0.0000000000000E+000
z**1 -1.0000000000000E+000
f0 5.00000000E+004 gain 2.0000E+000 DC gain 0.0000E+000
pole 5.5426517654291E-001 2.3606301674445E-001
q. f.
z**2 3.6293563380263E-001
z**1 -1.1085303530858E+000
f0 6.40813451E+003 gain 3.4615E+000 DC gain 3.9307E+000
zero -1.0000000000000E+000 0.0000000000000E+000
q. f.
z**2 0.0000000000000E+000
z**1 1.0000000000000E+000
f0 5.00000000E+004 gain 0.0000E+000 DC gain 2.0000E+000
zero 1.0000000000000E+000 0.0000000000000E+000
q. f.
z**2 0.0000000000000E+000
z**1 -1.0000000000000E+000
f0 5.00000000E+004 gain 2.0000E+000 DC gain 0.0000E+000
zero -1.0000000000000E+000 0.0000000000000E+000
q. f.
z**2 0.0000000000000E+000
z**1 1.0000000000000E+000
f0 5.00000000E+004 gain 0.0000E+000 DC gain 2.0000E+000
pole 9.9489363330242E-001 3.7693825022973E-003
q. f.
z**2 9.8982754983013E-001
z**1 -1.9897872666048E+000
f0 6.02992086E+001 gain 2.1509E+004 DC gain 2.4824E+004
zero 1.0000000000000E+000 0.0000000000000E+000
q. f.
z**2 0.0000000000000E+000
z**1 -1.0000000000000E+000
f0 5.00000000E+004 gain 2.0000E+000 DC gain 0.0000E+000
pole 6.8717139775357E-001 4.7464057507144E-001
q. f.
z**2 6.9748820539474E-001
z**1 -1.3743427955071E+000
f0 9.62040971E+003 gain 5.7679E+000 DC gain 3.0946E+000
zero -1.0000000000000E+000 0.0000000000000E+000
q. f.
z**2 0.0000000000000E+000
z**1 1.0000000000000E+000
f0 5.00000000E+004 gain 0.0000E+000 DC gain 2.0000E+000
zero 1.0000000000000E+000 0.0000000000000E+000
q. f.
z**2 0.0000000000000E+000
z**1 -1.0000000000000E+000
f0 5.00000000E+004 gain 2.0000E+000 DC gain 0.0000E+000
zero -1.0000000000000E+000 0.0000000000000E+000
q. f.
z**2 0.0000000000000E+000
z**1 1.0000000000000E+000
f0 5.00000000E+004 gain 0.0000E+000 DC gain 2.0000E+000
pole 9.9807271222275E-001 5.9857790942379E-003
q. f.
z**2 9.9618496843504E-001
z**1 -1.9961454244455E+000
f0 9.54494495E+001 gain 4.3163E+004 DC gain 2.5288E+004
zero 1.0000000000000E+000 0.0000000000000E+000
q. f.
z**2 0.0000000000000E+000
z**1 -1.0000000000000E+000
f0 5.00000000E+004 gain 2.0000E+000 DC gain 0.0000E+000
0.0 -999.99
2500.0 -0.00
5000.0 -0.00
7500.0 -0.19
10000.0 -3.01
12500.0 -11.06
15000.0 -19.84
17500.0 -27.87
20000.0 -35.29
22500.0 -42.33
25000.0 -49.20
27500.0 -56.06
30000.0 -63.09
32500.0 -70.50
35000.0 -78.52
37500.0 -87.51
40000.0 -98.06
42500.0 -111.21
45000.0 -129.27
47500.0 -159.65
50000.0 -1628.61
До 72дБ недотягивает, на 30К, но это же Баттерворт!