filtercoeff~ Reference

Signal-rate filter coefficient generator

filtercoeff~

Description

The filtercoeff~ object is a signal-rate filter coefficient calculator for the biquad~ object. It calculates the filter coefficients from three higher-level parameters: frequency, amplitude and resonance (Q) or slope (S). Its internal calculations are based on those of the filtergraph~ object.

Examples

The filtercoeff~ object lets you send sample-accurate coefficients to biquad~

Arguments

default-filter-type [symbol]

Optional

A symbol argument may be used to set the default filter type (highpass, lowpass, etc...).

resampling-factor [int]

Optional

An optional second argument can be used to specify a resampling factor.

Attributes

Common Box Attributes

Messages

int

Arguments

filter-parameters [int]
Integer values are converted to float.

In 1st inlet: Sets the center or cutoff frequency parameter for the filter and causes output.

In 2nd inlet: Sets the gain parameter for the filter and causes output.

In 3rd inlet: Sets the Q (resonance) or S (slope) parameter for the filter and causes output. (note that the term slope is only used for the third parameter of shelving filters, and is roughly equivalent to resonance).

float

Arguments

filter-parameters [float]
In 1st inlet: Sets the center or cutoff frequency parameter for the filter and causes output.

In 2nd inlet: Sets the gain parameter for the filter and causes output.

In 3rd inlet: Sets the Q (resonance) or S (slope) parameter for the filter and causes output. (note that the term slope is only used for the third parameter of shelving filters, and is roughly equivalent to resonance)

list

Arguments

center-frequency [float]
initial-gain [float]
Q [float]
A list of up to 3 floats will specify the center-frequency, the gain, and the Q-factor respectively. A signal connected to any inlet where these parameters would normally be received will override any input from a list and the effects of these parameters are completely dependent on what type of filter is chosen.

allpass

Arguments

center-frequency [float]
Q [float]
In left inlet: The word allpass sets the filter type to allpass mode. The frequency response of the filter is based on two parameters: center/cutoff frequency and Q (resonance). The gain parameter is set to unity gain (1.0). An allpass filter is designed to modify the phase response, leaving a flat amplitude response

bandpass

Arguments

center-frequency [float]
Q [float]
In left inlet: The word bandpass sets the filter type to bandpass mode. The frequency response of the filter is based on two parameters: center frequency and Q (resonance). The gain parameter is set to unity gain (1.0).

bandstop

Arguments

center-frequency [float]
Q [float]
In left inlet: The word bandstop sets the filter type to bandstop mode. The frequency response of the filter is based on two parameters: center frequency and Q (resonance). The gain parameter is set to unity gain (1.0).

gainapass

Arguments

center-frequency [float]
initial-gain [float]
Q [float]
In left inlet: The word gainapass sets the filter type to allpass mode with user-controllable gain. The frequency response of the filter is based on three parameters: center/cutoff frequency, gain, and Q (resonance), although only the gain parameter has an effect on the amplitude response. An allpass filter is designed to modify the phase response, leaving a flat amplitude response

gainbpass

Arguments

center-frequency [float]
initial-gain [float]
Q [float]
In left inlet: The word gainbpass sets the filter type to bandpass mode with user-controllable gain. The frequency response of the filter is based on three parameters: center frequency, gain, and Q (resonance).

gainbstop

Arguments

center-frequency [float]
initial-gain [float]
Q [float]
In left inlet: The word gainbstop sets the filter type to bandstop mode with user-controllable gain. The frequency response of the filter is based on three parameters: center frequency, gain, and Q (resonance).

gainhpass

Arguments

center-frequency [float]
initial-gain [float]
Q [float]
In left inlet: The word gainhpass sets the filter type to highpass mode with user-controllable gain. The frequency response of the filter is based on three parameters: cf (cutoff frequency) gain, and Q (resonance).

gainlpass

Arguments

center-frequency [float]
initial-gain [float]
Q [float]
In left inlet: The word gainlpass sets the filter type to lowpass mode with user-controllable gain. The frequency response of the filter is based on three parameters: cf (cutoff frequency) gain, and Q (resonance).

gainresonant

Arguments

center-frequency [float]
initial-gain [float]
Q [float]
In left inlet: The word gainrtesonant sets the filter type to resonant mode (resonant bandpass filter) with user-controllable gain. The frequency response of the filter is based on three parameters: center frequency, gain, and Q (resonance).

highpass

Arguments

center-frequency [float]
Q [float]
In left inlet: The word highpass sets the filter type to highpass mode. The frequency response of the filter is based on two parameters: cf (cutoff frequency) and Q (resonance). The gain parameter is set to unity gain (1.0).

highshelf

Arguments

center-frequency [float]
initial-gain [float]
Q [float]
In left inlet: The word highshelf sets the filter type to highshelf mode. The frequency response of the filter is based on three parameters: cutoff frequency, gain, and S (slope).

lowpass

Arguments

center-frequency [float]
Q [float]
In left inlet: The word lowpass sets the filter type to lowpass mode. The frequency response of the filter is based on two parameters: cf (cutoff frequency) and Q (resonance). The gain parameter is set to unity gain (1.0).

lowshelf

Arguments

center-frequency [float]
initial-gain [float]
Q [float]
In left inlet: The word lowshelf sets the filter type to lowshelf mode. The frequency response of the filter is based on three parameters: cutoff frequency, gain, and S (slope).

off

Arguments

filter-type [list]
In left inlet: The word off sets the filter type to off mode whereby the dry, unfiltered signal is passed to the outputs.

peaknotch

Arguments

center-frequency [float]
initial-gain [float]
Q [float]
In left inlet: The word peaknotch sets the filter type to peaknotch mode. The frequency response of the filter is based on three parameters: center/cutoff frequency, gain, and Q (resonance).

resamp

Arguments

resampling-factor [int]
Set the resampling factor

resonant

Arguments

center-frequency [float]
Q [float]
In left inlet: The word resonant sets the filter type to resonant mode (resonant bandpass filter). The frequency response of the filter is based on two parameters: center frequency and Q (resonance). The gain parameter is set to unity gain (1.0).

signal

In 1st inlet: Sets the center or cutoff frequency parameter for the filter and causes output.

In 2nd inlet: Sets the gain parameter for the filter and causes output.

In 3rd inlet: Sets the Q (resonance) or S (slope) parameter for the filter and causes output. (note that the term slope is only used for the third parameter of shelving filters, and is roughly equivalent to resonance)

Output

signal

The five signal outlets output signal-rate filter coefficients for the biquad~ object.

See Also

Name Description
Sound Processing Techniques Sound Processing Techniques
allpass~
biquad~
cascade~
delay~
filtergraph~
lores~
reson~
teeth~
Audio Filtering Audio Filtering