Multi-channel biquad filter with multiple types and slopes. More...

#include <gin_filter.h>

Public Types
enum	Type { none = 0 , lowpass , highpass , bandpass , notch , lowshelf , highshelf , peak , allpass }

enum	Slope { db12 = 0 , db24 }

Public Member Functions
	Filter (int maxOrder=2)

void	setSampleRate (double sr)

void	setNumChannels (int ch)

void	setType (Type t)

void	setSlope (Slope s)

void	reset ()

float	getFrequency ()

void	setParams (float freq_, float q_, float g_=0.0f)

void	process (juce::AudioSampleBuffer &buffer)

float	getResponseMagnitude (float atFreq)

Detailed Description

Multi-channel biquad filter with multiple types and slopes.

Filter provides a flexible multi-channel filtering solution supporting common filter types (lowpass, highpass, bandpass, etc.) with selectable 12dB or 24dB/octave slopes. It uses high-quality biquad filters with matched z-transform (MZTi) coefficient calculation.

Key Features:

Multiple filter types (8 types available)
12dB or 24dB/octave slopes
Multi-channel processing
Frequency response calculation
Low/high shelving and parametric peak
Real-time parameter updates

Filter Types:

lowpass: Remove frequencies above cutoff
highpass: Remove frequencies below cutoff
bandpass: Keep only frequencies near center
notch: Remove frequencies near center
lowshelf: Boost/cut low frequencies
highshelf: Boost/cut high frequencies
peak: Boost/cut at specific frequency
allpass: Phase shift without amplitude change

Slopes:

db12: 12dB/octave (one biquad stage)
db24: 24dB/octave (two biquad stages)

Usage:

Filter filter;
filter.setSampleRate(44100.0);
filter.setNumChannels(2);
filter.setType(Filter::lowpass);
filter.setSlope(Filter::db24);
filter.setParams(1000.0f, 0.707f); // 1kHz, Q=0.707
 
filter.process(audioBuffer);
 
// Get frequency response at 500Hz
float response = filter.getResponseMagnitude(500.0f);

See also: EQ

Member Enumeration Documentation

◆ Type

enum Filter::Type

Enumerator
none
lowpass
highpass
bandpass
notch
lowshelf
highshelf
peak
allpass

◆ Slope

enum Filter::Slope

Enumerator
db12
db24

Constructor & Destructor Documentation

◆ Filter()

Filter::Filter ( int maxOrder = 2 )

Member Function Documentation

◆ setSampleRate()

void Filter::setSampleRate ( double sr )

◆ setNumChannels()

void Filter::setNumChannels ( int ch )

References Point< T >::Point().

◆ setType()

void Filter::setType ( Type t )

◆ setSlope()

void Filter::setSlope ( Slope s )

◆ reset()

void Filter::reset ( )

◆ getFrequency()

float Filter::getFrequency ( )

◆ setParams()

void Filter::setParams	(	float	freq_,
		float	q_,
		float	g_ = `0.0f`
	)

References none, and Q.

◆ process()

void Filter::process ( juce::AudioSampleBuffer & buffer )

References db12, db24, and none.

◆ getResponseMagnitude()

float Filter::getResponseMagnitude ( float atFreq )

References db12, db24, Point< T >::Point(), and Q.

The documentation for this class was generated from the following file:

gin_filter.h

Public Types

Public Member Functions