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<refentry id="resony">
<indexterm id="IndexResony"><primary>resony</primary></indexterm>
<refentryinfo><title>Signal Modifiers:Standard Filters:Resonant</title></refentryinfo>
<refmeta>
<refentrytitle>resony</refentrytitle>
</refmeta>
<refnamediv>
<refname>resony</refname>
<refpurpose>
A bank of second-order bandpass filters, connected in parallel.
</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<para>
A bank of second-order bandpass filters, connected in parallel.
</para>
</refsect1>
<refsect1>
<title>Syntax</title>
<synopsis>ares <command>resony</command> asig, kbf, kbw, inum, ksep [, isepmode] [, iscl] [, iskip]</synopsis>
</refsect1>
<refsect1>
<title>Initialization</title>
<para>
<emphasis>inum</emphasis> -- number of filters
</para>
<para>
<emphasis>isepmode</emphasis> (optional, default=0) -- if <emphasis>isepmode</emphasis> = 0, the separation of center frequencies of each filter is generated logarithmically (using octave as unit of measure). If <emphasis>isepmode</emphasis> not equal to 0, the separation of center frequencies of each filter is generated linearly (using Hertz). Default value is 0.
</para>
<para>
<emphasis>iscl</emphasis> (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 <emphasis>kcf</emphasis> 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 (e.g. <link linkend="balance"><citetitle>balance</citetitle></link>). The default value is 0.
</para>
<para>
<emphasis>iskip</emphasis> (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.
</para>
</refsect1>
<refsect1>
<title>Performance</title>
<para>
<emphasis>asig</emphasis> -- audio input signal
</para>
<para>
<emphasis>kbf</emphasis> -- base frequency, i.e. center frequency of lowest filter in Hz
</para>
<para>
<emphasis>kbw</emphasis> -- bandwidth in Hz
</para>
<para>
<emphasis>ksep</emphasis> -- separation of the center frequency of filters in octaves
</para>
<para>
<emphasis>resony</emphasis> is a bank of second-order bandpass filters, with k-rate variant frequency separation, base frequency and bandwidth, connected in parallel (i.e. the resulting signal is a mix of the output of each filter). The center frequency of each filter depends of <emphasis>kbf</emphasis> and <emphasis>ksep</emphasis> variables. The maximum number of filters is set to 100.
</para>
</refsect1>
<refsect1>
<title>Examples</title>
<para>
Here is an example of the resony opcode. It uses the file <ulink url="examples/resony.csd"><citetitle>resony.csd</citetitle></ulink>.
<example>
<title>Example of the resony opcode.</title>
<para>See the sections <link linkend="UsingRealTime"><citetitle>Real-time Audio</citetitle></link> and <link linkend="CommandFlags"><citetitle>Command Line Flags</citetitle></link> for more information on using command line flags.</para>
<xi:include href="examples-xml/resony.csd.xml" xmlns:xi="http://www.w3.org/2001/XInclude"/>
</example>
</para>
</refsect1>
<refsect1>
<title>Credits</title>
<para>
<simplelist>
<member>Author: &namegabriel;</member>
<member>Italy</member>
<member>1999</member>
</simplelist>
</para>
<para>New in Csound version 3.56</para>
</refsect1>
</refentry>
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