rsc3/doc-schelp/HelpSource/Classes/BLowShelf.scrbl

75 lines
1.9 KiB
Racket

#lang scribble/manual
@(require (for-label racket))
@title{BLowShelf}
Low Shelf@section{categories}
UGens>Filters>BEQSuite
@section{related}
Classes/SOS, Classes/BLowPass, Classes/BLowPass4, Classes/BHiPass, Classes/BHiPass4, Classes/BPeakEQ, Classes/BHiShelf, Classes/BBandPass, Classes/BBandStop, Classes/BAllPass
@section{description}
The B equalization suite is based on the Second Order Section (link::Classes/SOS::) biquad UGen.
@section{note}
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.
::
@section{classmethods}
@section{method}
ar
@section{argument}
in
input signal to be processed.
@section{argument}
freq
center frequency.
WARNING: due to the nature of its implementation frequency values close to 0 may cause glitches and/or extremely loud audio artifacts!
@section{argument}
rs
the reciprocal of S. Shell boost/cut slope. When S = 1, the shelf slope is as steep as it can be and remain monotonically increasing or decreasing gain with frequency. The shelf slope, in dB/octave, remains proportional to S for all other values for a fixed
@racketblock[freq/SampleRate.ir:: and ]
@racketblock[db::.
]
@section{argument}
db
gain. boost/cut the center frequency in dBs.
@section{argument}
mul
@section{argument}
add
@section{examples}
@racketblock[
s.boot;
(
z = { // toy around with boost/cut
BLowShelf.ar(
SoundIn.ar([0,1]),
MouseX.kr(40, 6000, \exponential),
1.0, // rs
MouseY.kr(24.0, -24.0, \linear),
0.5); // mul
}.play)
z.release;
(
z = { // toy around with rs
BLowShelf.ar(
SoundIn.ar([0,1]),
MouseX.kr(20, 6000, \exponential),
MouseY.kr(0.1, 1.0, \linear), // rs
6,
0.5); // mul
}.play)
z.release;
::
]