RNBO Objects & Operators filtercoeff~
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filtercoeff~

Calculate filter coefficients for a biquad filter

Arguments

type [enum]

Optional

A symbol argument may be used to set the default filter type. Acceptable values are...

'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': 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': 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': 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': 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': 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': 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': 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': 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': 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': 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': 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': 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': Sets the filter type to off mode whereby the dry, unfiltered signal is passed to the outputs.

resamp [number]

Optional

An optional second argument can be used to specify a resampling factor. Makes only sense when uses as a DSP (tilde) operator

Inlets

frequency [auto]

Sets the center or cutoff frequency parameter for the filter and causes output.

gain [auto]

Sets the gain parameter for the filter and causes output.

q [auto]

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).

Outlets

out1 [signal]

Signal-rate FF0 Coefficient. Patches into Gain inlet of the biquad~ object

out2 [signal]

Signal-rate FF1 Coefficient. Patches into FF1 inlet of the biquad~ object

out3 [signal]

Signal-rate FF2 Coefficient. Patches into FF2 inlet of the biquad~ object

out4 [signal]

Signal-rate FB1 Coefficient. Patches into FB1 inlet of the biquad~ object

out5 [signal]

Signal-rate FB2 Coefficient. Patches into FB2 inlet of the biquad~ object

Fixed Attributes

These attributes must be set in the object box and determine the behavior of the object at runtime.

resamp [number] (default: -1)

An optional second argument can be used to specify a resampling factor. Makes only sense when uses as a DSP (tilde) operator

Dynamic Attributes

These attributes can be modified in the code during execution using the set object

frequency [auto]

Sets the center or cutoff frequency parameter for the filter and causes output.

gain [auto]

Sets the gain parameter for the filter and causes output.

q [auto]

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).

reset [bang] (default: 0)

Banging this attribute will reset the object to its default state.

type [enum] (default: lowpass)

A symbol argument may be used to set the default filter type. Acceptable values are...

'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': 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': 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': 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': 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': 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': 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': 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': 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': 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': 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': 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': 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': Sets the filter type to off mode whereby the dry, unfiltered signal is passed to the outputs.

Possible values:

0 = 'lowpass'
1 = 'highpass'
2 = 'bandpass'
3 = 'bandstop'
4 = 'peaknotch'
5 = 'lowshelf'
6 = 'highshelf'
7 = 'resonant'
8 = 'allpass'
9 = 'gainlpass'
10 = 'gainhpass'
11 = 'gainbpass'
12 = 'gainbstop'
13 = 'gainresonant'
14 = 'gainapass'
15 = 'off'