index :: flt

flt.c_lpf

aliases: [ceammc/lpf->biquad], [lpf->biquad]

LPF coefficient calculator for biquad filter

available since version: 0.9.2

---

information

Calculates coefficients for transfer function: H(z)=(b0 + b1z⁻¹ + b2z⁻²)/(1 + a1z⁻¹ + a2z⁻²)

arguments:

• FREQ center frequency
  type: float
  units: Hz
  

methods:

• bw set bandwidth in octaves
  parameters:
  • OCT bandwidth
    type: float
    required: True
    

properties:

• @freq Get/set center frequency
  type: float
  units: Hz
  range: 20..22050
  default: 1000
  

• @q Get/set quality factor: @freq/BANDWIDTH
  type: float
  range: 0.01..100
  default: 0.7071
  

• @rad (initonly) Get/set use angular frequency
  type: flag
  

inlets:

• filter frequency
  type: control

outlets:

• list: b0 b1 b2 a1 a2
  type: control

keywords:

filter biquad lowpass

See also: [flt.c_hpf]

Authors: Serge Poltavsky

License: GPL3 or later