| Trilobite 1.4 User Guide | © Darwin Arts L.L.C., 2016

# Biquad Filter Module

The Biquad Filter Module implements a subtractive synthesis six-coefficient digital IIR filter with input/output power balancing for some pole stability. It takes an input signal and several continuous real-time parameter values and produces a filtered output Signal. Available forms of the filter include: Lowpass, Highpass, Bandpass, Notch, and Allpass. For more information about IIR filter forms and configurations, see Robert Bristow-Johnson's excellent EQ Cookbook.

For a key to understanding the tables on this page, see the Module Types page.

## Adding Input Ports

Adding input ports is not enabled for this module.

## Static Parameters

  # | Title | Type | Description
  0 | Filter Type | Choice | Has the options Lowpass Highpass Bandpass Notch Allpass

## Input Ports

  # | Title | Description | Input Scalar Used | Parameter Scalar Used
  0 | Center Frequency | Indicates the filter center frequency in Hz (cycles per second) for each filter form | YES | YES
  1 | Q | Indicates the 'Quality value' of the filter | YES | YES
  2 | (unused) | Future feature placeholder. | N/A | N/A
  3 | Input Signal | Any input signal. | NO | NO

## Output Ports

  # | Title | Description
  0 | Filtered Signal | A filtered and power-balanced version of the Input Signal