59 lines
1.6 KiB
Text
59 lines
1.6 KiB
Text
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#lang scribble/manual
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@(require (for-label racket))
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@title{BLowPass4}
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24db/oct rolloff - 4th order resonant Low Pass Filter [1]@section{categories}
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UGens>Filters>BEQSuite
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@section{related}
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Classes/SOS, Classes/BLowPass, Classes/BHiPass, Classes/BHiPass4, Classes/BPeakEQ, Classes/BLowShelf, Classes/BHiShelf, Classes/BBandPass, Classes/BBandStop, Classes/BAllPass
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@section{description}
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The B equalization suite is based on the Second Order Section (link::Classes/SOS::) biquad UGen.
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@section{note}
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Biquad coefficient calculations imply certain amount of CPU overhead. These plugin UGens contain optimizations such that the coefficients get updated only when there has been a change to one of the filter's parameters. This can cause spikes in CPU performance and should be considered when using several of these units.
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::
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[1] this is a composite pseudo link::Classes/UGen::. BLowPass4 is built by cascading 2 link::Classes/SOS:: sections.
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@section{classmethods}
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@section{method}
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ar
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@section{argument}
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in
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input signal to be processed.
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@section{argument}
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freq
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cutoff frequency.
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WARNING: due to the nature of its implementation frequency values close to 0 may cause glitches and/or extremely loud audio artifacts!
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@section{argument}
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rq
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the reciprocal of Q. bandwidth / cutoffFreq.
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@section{argument}
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mul
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@section{argument}
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add
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@section{examples}
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@racketblock[
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s.boot;
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(
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z = {
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BLowPass4.ar(
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SoundIn.ar([0,1]),
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MouseX.kr(10, 20000, \exponential), // cutoff freq.
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MouseY.kr(0.1, 1.0, \linear), // rq - compensate for 2 biquad sections.
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0.5); // mul
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}.play)
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z.release;
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::
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]
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