<!-- Converted to DocBook/SGML by Kevin Conder -->
<refentry id="valpass">
  <refmeta>
    <refentrytitle>valpass</refentrytitle>
  </refmeta>
 
  <refnamediv>
    <refname>valpass</refname>
    <refpurpose>
      Variably reverberates an input signal with a flat frequency response.
      <indexterm id="IndexValpass"><primary>valpass</primary></indexterm>
    </refpurpose>
  </refnamediv>
 
  <refsect1>
    <title>Description</title>
    <para>
      Variably reverberates an input signal with a flat frequency response.
    </para>
  </refsect1>
 
  <refsect1>
    <title>Syntax</title>
    <synopsis>ar <command>valpass</command> asig, krvt, xlpt, imaxlpt [, iskip] [, insmps]</synopsis>
  </refsect1>
 
  <refsect1>
    <title>Initialization</title>
    <para>
      <emphasis>imaxlpt</emphasis> -- maximum loop time for <emphasis>klpt</emphasis>
    </para>

    <para>
      <emphasis>iskip</emphasis> (optional, default=0) -- initial disposition of delay-loop data space (cf. <link linkend="reson"><citetitle>reson</citetitle></link>). The default value is 0.
    </para>

    <para>
      <emphasis>insmps</emphasis> (optional, default=0) -- delay amount, as a number of samples.
    </para>
  </refsect1>
 
  <refsect1>
    <title>Performance</title>
    <para>
      <emphasis>krvt</emphasis> -- the reverberation time (defined as the time in seconds for a signal to decay to 1/1000, or 60dB down from its original amplitude).
    </para>

    <para>
      <emphasis>xlpt</emphasis> -- variable loop time in seconds, same as <emphasis>ilpt</emphasis> in <emphasis>comb</emphasis>.  Loop time can be as large as <emphasis>imaxlpt</emphasis>.
    </para>

    <para>
      This filter reiterates input with an echo density determined by loop time <emphasis>ilpt</emphasis>. The attenuation rate is independent and is determined by <emphasis>krvt</emphasis>, the reverberation time (defined as the time in seconds for a signal to decay to 1/1000, or 60dB down from its original amplitude). Its output will begin to appear immediately.
    </para>
  </refsect1>

  <refsect1>
    <title>See Also</title>
    <para>
      <link linkend="alpass"><citetitle>alpass</citetitle></link>,
      <link linkend="comb"><citetitle>comb</citetitle></link>,
      <link linkend="reverb"><citetitle>reverb</citetitle></link>,
      <link linkend="vcomb"><citetitle>vcomb</citetitle></link>
    </para>
  </refsect1>

  <refsect1>
    <title>Credits</title>
    <para>
      <simplelist>
        <member>Author: William <quote>Pete</quote> Moss</member>
        <member>University of Texas at Austin</member>
        <member>Austin, Texas USA</member>
        <member>January 2002</member>
      </simplelist>
    </para>
  </refsect1>
</refentry>
