<?xml version="1.0" encoding="UTF-8" standalone="no"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> <title>reson</title> <link rel="stylesheet" type="text/css" href="csound.css" /> <link rel="stylesheet" type="text/css" href="syntax-highlighting.css" /> <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot" /> <link rel="home" href="index.html" title="The Canonical Csound Reference Manual" /> <link rel="up" href="OpcodesTop.html" title="Orchestra Opcodes and Operators" /> <link rel="prev" href="repluck.html" title="repluck" /> <link rel="next" href="resonk.html" title="resonk" /> </head> <body> <div class="navheader"> <table width="100%" summary="Navigation header"> <tr> <th colspan="3" align="center">reson</th> </tr> <tr> <td width="20%" align="left"><a accesskey="p" href="repluck.html">Prev</a> </td> <th width="60%" align="center">Orchestra Opcodes and Operators</th> <td width="20%" align="right"> <a accesskey="n" href="resonk.html">Next</a></td> </tr> </table> <hr /> </div> <div class="refentry"> <a id="reson"></a> <div class="titlepage"></div> <a id="IndexReson" class="indexterm"></a> <div class="refnamediv"> <h2> <span class="refentrytitle">reson</span> </h2> <p>reson — A second-order resonant filter. </p> </div> <div class="refsect1"> <a id="idm281472895553768"></a> <h2>Description</h2> <p> A second-order resonant filter. </p> </div> <div class="refsect1"> <a id="idm281472895552456"></a> <h2>Syntax</h2> <pre class="synopsis">ares <span class="command"><strong>reson</strong></span> asig, xcf, xbw [, iscl] [, iskip]</pre> </div> <div class="refsect1"> <a id="idm281472895480984"></a> <h2>Initialization</h2> <p> <span class="emphasis"><em>iscl</em></span> (optional, default=0) -- coded scaling factor for resonators. A value of 1 signifies a peak response factor of 1, i.e. all frequencies other than kcf are attenuated in accordance with the (normalized) response curve. A value of 2 raises the response factor so that its overall RMS value equals 1. (This intended equalization of input and output power assumes all frequencies are physically present; hence it is most applicable to white noise.) A zero value signifies no scaling of the signal, leaving that to some later adjustment (see <a class="link" href="balance.html" title="balance"><em class="citetitle">balance</em></a>). The default value is 0. </p> <p> <span class="emphasis"><em>iskip</em></span> (optional, default=0) -- initial disposition of internal data space. Since filtering incorporates a feedback loop of previous output, the initial status of the storage space used is significant. A zero value will clear the space; a non-zero value will allow previous information to remain. The default value is 0. </p> </div> <div class="refsect1"> <a id="idm281472895476328"></a> <h2>Performance</h2> <p> <span class="emphasis"><em>ares</em></span> -- the output signal at audio rate. </p> <p> <span class="emphasis"><em>asig</em></span> -- the input signal at audio rate. </p> <p> <span class="emphasis"><em>xcf</em></span> -- the center frequency of the filter, or frequency position of the peak response. </p> <p> <span class="emphasis"><em>xbw</em></span> -- bandwidth of the filter (the Hz difference between the upper and lower half-power points). </p> <p> <span class="emphasis"><em>reson</em></span> is a second-order filter in which <span class="emphasis"><em>kcf</em></span> controls the center frequency, or frequency position of the peak response, and <span class="emphasis"><em>kbw</em></span> controls its bandwidth (the frequency difference between the upper and lower half-power points). </p> </div> <div class="refsect1"> <a id="idm281472895469752"></a> <h2>Examples</h2> <p> Here is an example of the reson opcode. It uses the file <a class="ulink" href="examples/reson.csd" target="_top"><em class="citetitle">reson.csd</em></a>. </p> <div class="example"> <a id="idm281472895467976"></a> <p class="title"> <strong>Example 822. Example of the reson opcode.</strong> </p> <div class="example-contents"> <p>See the sections <a class="link" href="UsingRealTime.html" title="Real-Time Audio"><em class="citetitle">Real-time Audio</em></a> and <a class="link" href="CommandFlags.html" title="Csound command line"><em class="citetitle">Command Line Flags</em></a> for more information on using command line flags.</p> <div class="refsect1"> <a id="idm281472716643112"></a> <pre class="programlisting"> <span class="nt"><CsoundSynthesizer></span> <span class="nt"><CsOptions></span> <span class="c1">; Select audio/midi flags here according to platform</span> -odac <span class="c1">;;;realtime audio out</span> <span class="c1">;-iadc ;;;uncomment -iadc if realtime audio input is needed too</span> <span class="c1">; For Non-realtime ouput leave only the line below:</span> <span class="c1">; -o reson.wav -W ;;; for file output any platform</span> <span class="nt"></CsOptions></span> <span class="nt"><CsInstruments></span> <span class="vg">sr</span> <span class="o">=</span> <span class="mi">44100</span> <span class="vg">ksmps</span> <span class="o">=</span> <span class="mi">32</span> <span class="vg">0dbfs</span> <span class="o">=</span> <span class="mi">1</span> <span class="vg">nchnls</span> <span class="o">=</span> <span class="mi">2</span> <span class="kd">instr</span> <span class="nf">1</span> a<span class="n">saw</span> <span class="nb">vco2</span> <span class="mf">.2</span><span class="p">,</span> <span class="mi">220</span> <span class="c1">;sawtooth</span> k<span class="n">cf</span> <span class="nb">line</span> <span class="mi">220</span><span class="p">,</span> <span class="nb">p3</span><span class="p">,</span> <span class="mi">1760</span> <span class="c1">;vary cut-off frequency from 220 to 1280 Hz</span> k<span class="n">bw</span> <span class="o">=</span> <span class="nb">p4</span> <span class="c1">;vary bandwidth of filter too </span> a<span class="n">res</span> <span class="nb">reson</span> a<span class="n">saw</span><span class="p">,</span> k<span class="n">cf</span><span class="p">,</span> k<span class="n">bw</span> a<span class="n">sig</span> <span class="nb">balance</span> a<span class="n">res</span><span class="p">,</span> a<span class="n">saw</span> <span class="nb">outs</span> a<span class="n">sig</span><span class="p">,</span> a<span class="n">sig</span> <span class="kd">endin</span> <span class="nt"></CsInstruments></span> <span class="nt"><CsScore></span> <span class="nb">i</span> <span class="mi">1</span> <span class="mi">0</span> <span class="mi">4</span> <span class="mi">10</span> <span class="c1">;bandwidth of filter = 10 Hz</span> <span class="nb">i</span> <span class="mi">1</span> <span class="o">+</span> <span class="mi">4</span> <span class="mi">50</span> <span class="c1">;50 Hz and</span> <span class="nb">i</span> <span class="mi">1</span> <span class="o">+</span> <span class="mi">4</span> <span class="mi">200</span> <span class="c1">;200 Hz</span> <span class="nb">e</span> <span class="nt"></CsScore></span> <span class="nt"></CsoundSynthesizer></span> </pre> </div> </div> </div> <p><br class="example-break" /> </p> </div> <div class="refsect1"> <a id="idm281472895463656"></a> <h2>See Also</h2> <p> <a class="link" href="areson.html" title="areson"><em class="citetitle">areson</em></a>, <a class="link" href="aresonk.html" title="aresonk"><em class="citetitle">aresonk</em></a>, <a class="link" href="atone.html" title="atone"><em class="citetitle">atone</em></a>, <a class="link" href="atonek.html" title="atonek"><em class="citetitle">atonek</em></a>, <a class="link" href="port.html" title="port"><em class="citetitle">port</em></a>, <a class="link" href="portk.html" title="portk"><em class="citetitle">portk</em></a>, <a class="link" href="resonk.html" title="resonk"><em class="citetitle">resonk</em></a>, <a class="link" href="tone.html" title="tone"><em class="citetitle">tone</em></a>, <a class="link" href="tonek.html" title="tonek"><em class="citetitle">tonek</em></a> </p> </div> <div class="refsect1"> <a id="idm281472895453864"></a> <h2>Credits</h2> <p>Audio rate parameters introduced in version 6.02</p> <p>November 2013.</p> </div> </div> <div class="navfooter"> <hr /> <table width="100%" summary="Navigation footer"> <tr> <td width="40%" align="left"><a accesskey="p" href="repluck.html">Prev</a> </td> <td width="20%" align="center"> <a accesskey="u" href="OpcodesTop.html">Up</a> </td> <td width="40%" align="right"> <a accesskey="n" href="resonk.html">Next</a></td> </tr> <tr> <td width="40%" align="left" valign="top">repluck </td> <td width="20%" align="center"> <a accesskey="h" href="index.html">Home</a> </td> <td width="40%" align="right" valign="top"> resonk</td> </tr> </table> </div> </body> </html>