Butterworth IIR filter, sampling rate 8000.0 Hz, scale to suit
Filter type: LP
Passband: 0 - 1000 Hz
Order: 4
Coefficients
a[0] = 0.010209485     	b[0] = 1.0
a[1] = 0.04083794     	b[1] = -1.9684278
a[2] = 0.061256908     	b[2] = 1.7358607
a[3] = 0.04083794     	b[3] = -0.72447085
a[4] = 0.010209485     	b[4] = 0.1203896
Chebyshev IIR filter, sampling rate 8000.0 Hz, scale to suit
Filter type: LP
Passband: 0 - 1000 Hz
Passband ripple: 1.0 dB
Order: 4
Coefficients
a[0] = 0.0042412407     	b[0] = 1.0
a[1] = 0.016964963     	b[1] = -2.7280328
a[2] = 0.025447443     	b[2] = 3.2549775
a[3] = 0.016964963     	b[3] = -1.9259477
a[4] = 0.0042412407     	b[4] = 0.47514287