filtercoeff~

Signal-rate filter coefficient generator

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.

Arguments

Name Type Opt Description
default-filter-type symbol opt A symbol argument may be used to set the default filter type (highpass, lowpass, etc...).
resampling-factor int opt Used as a resampling factor.

Messages

int filter-parameters [int]
Converted to float.
float 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 filter-parameters [list]
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.
bandpass filter-type [list]
In left inlet: The word bandpass sets the filter type to bandpass mode. The frequency response of the filter is based on two parameters: cf (center frequency) and Q (resonance). The gain parameter is set to unity gain (1.0).
bandstop filter-type [list]
In left inlet: The word bandstop sets the filter type to bandstop mode. The frequency response of the filter is based on two parameters: cf (center frequency) and Q (resonance). The gain parameter is set to unity gain (1.0).
allpass filter-type [list]
In left inlet: The word allpass sets the filter type to allpass mode. The frequency response of the filter is based on two parameters: cf (center frequency, or 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
highpass filter-type [list]
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 filter-type [list]
In left inlet: The word highshelf sets the filter type to highshelf mode. The frequency response of the filter is based on three parameters: cf (cutoff frequency) gain, and S (slope).
gainbpass filter-type [list]
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: cf (center frequency) gain, and Q (resonance).
gainbstop filter-type [list]
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: cf (center frequency) gain, and Q (resonance).
gainapass filter-type [list]
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: cf (center frequency, or 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
gainhpass filter-type [list]
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 filter-type [list]
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 filter-type [list]
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: cf (center frequency) gain, and Q (resonance).
lowpass filter-type [list]
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 filter-type [list]
In left inlet: The word lowshelf sets the filter type to lowshelf mode. The frequency response of the filter is based on three parameters: cf (cutoff frequency) gain, and S (slope).
peaknotch filter-type [list]
In left inlet: The word peaknotch sets the filter type to peaknotch mode. The frequency response of the filter is based on three parameters: cf (center frequency) gain, and Q (resonance).
off 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.
resamp resampling-factor [int]
Sets the resampling factor.
resonant filter-type [list]
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: cf (center frequency) and Q (resonance). The gain parameter is set to unity gain (1.0).
signal Performs the same function as a float corresponding to each inlet.

Information for box attributes common to all objects

Output

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

Examples

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

See Also

Name Description
allpass~ Allpass filter
biquad~ Two-pole, two-zero filter
cascade~ Cascaded series of biquad filters
delay~ Delay line specified in samples or Max tempo-relative time format
filtergraph~ Graphical filter editor
lores~ Resonant lowpass filter
reson~ Resonant bandpass filter
teeth~ Comb filter with feedforward and feedback delay control