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<h2>
<span class="refentrytitle">ampdb</span>
</h2>
<p>ampdb —
Returns the amplitude equivalent of the decibel value x.
</p>
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<div class="refsect1" title="Description">
<a id="idp13504632"></a>
<h2>Description</h2>
<p>
Returns the amplitude equivalent of the decibel value x. Thus:
</p>
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<li class="listitem">
<p>60 dB = 1000</p>
</li>
<li class="listitem">
<p>66 dB = 1995.262</p>
</li>
<li class="listitem">
<p>72 dB = 3891.07</p>
</li>
<li class="listitem">
<p>78 dB = 7943.279</p>
</li>
<li class="listitem">
<p>84 dB = 15848.926</p>
</li>
<li class="listitem">
<p>90 dB = 31622.764</p>
</li>
</ul>
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<p>
</p>
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<div class="refsect1" title="Syntax">
<a id="idp13547480"></a>
<h2>Syntax</h2>
<pre class="synopsis"><span class="command"><strong>ampdb</strong></span>(x) (no rate restriction)</pre>
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<div class="refsect1" title="Examples">
<a id="idp13548456"></a>
<h2>Examples</h2>
<p>
Here is an example of the ampdb opcode. It uses the file <a class="ulink" href="examples/ampdb.csd" target="_top"><em class="citetitle">ampdb.csd</em></a>.
</p>
<div class="example">
<a id="idp13549432"></a>
<p class="title">
<strong>Example 46. Example of the ampdb 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>
<pre class="programlisting">
<span class="csdtag"><CsoundSynthesizer></span>
<span class="csdtag"><CsOptions></span>
<span class="comment">; Select audio/midi flags here according to platform</span>
-odac <span class="comment">;;;RT audio out</span>
<span class="comment">;-iadc ;;;uncomment -iadc if RT audio input is needed too</span>
<span class="comment">; For Non-realtime ouput leave only the line below:</span>
<span class="comment">; -o ampdb.wav -W ;;; for file output any platform</span>
<span class="csdtag"></CsOptions></span>
<span class="csdtag"><CsInstruments></span>
<span class="ohdr">sr</span> <span class="op">=</span> 44100
<span class="ohdr">ksmps</span> <span class="op">=</span> 32
<span class="ohdr">nchnls</span> <span class="op">=</span> 2
<span class="oblock">instr</span> 1
idb <span class="op">=</span> p4
iamp <span class="op">=</span> <span class="opc">ampdb</span>(idb)
asig <span class="opc">oscil</span> iamp, 220, 1
<span class="opc">print</span> iamp
<span class="opc">outs</span> asig, asig
<span class="oblock">endin</span>
<span class="csdtag"></CsInstruments></span>
<span class="csdtag"><CsScore></span>
<span class="comment">;sine wave.</span>
<span class="stamnt">f</span> 1 0 16384 10 1
<span class="stamnt">i</span> 1 0 1 50
<span class="stamnt">i</span> 1 + 1 90
<span class="stamnt">i</span> 1 + 1 68
<span class="stamnt">i</span> 1 + 1 80
<span class="stamnt">e</span>
<span class="csdtag"></CsScore></span>
<span class="csdtag"></CsoundSynthesizer></span>
</pre>
</div>
</div>
<p><br class="example-break" />
Its output should include lines like:
</p>
<pre class="screen">
instr 1: iamp = 316.228
instr 1: iamp = 31622.763
instr 1: iamp = 2511.886
instr 1: iamp = 9999.996
</pre>
<p>
</p>
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<div class="refsect1" title="See Also">
<a id="idp13552256"></a>
<h2>See Also</h2>
<p>
<a class="link" href="ampdbfs.html" title="ampdbfs"><em class="citetitle">ampdbfs</em></a>,
<a class="link" href="db.html" title="db"><em class="citetitle">db</em></a>,
<a class="link" href="dbamp.html" title="dbamp"><em class="citetitle">dbamp</em></a>,
<a class="link" href="dbfsamp.html" title="dbfsamp"><em class="citetitle">dbfsamp</em></a>
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