103 lines
5.1 KiB
HTML
103 lines
5.1 KiB
HTML
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<!doctype HTML public "-//W3C//DTD HTML 4.0 Frameset//EN">
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<html>
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<head>
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<meta http-equiv="Content-Type" content="text/html; charset=windows-1252">
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<meta name="generator" content="Adobe RoboHelp 9">
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<title>Leveller</title>
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<link rel="StyleSheet" href="HtmlHelp.css" type="text/css">
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<style title="hcp" type="text/css">
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<!--
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font.hcp1 { font-family:Arial; }
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font.hcp2 { font-size:small; }
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img.hcp3 { margin-top:0px;
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margin-bottom:0px;
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margin-left:0px;
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margin-right:0px; }
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p.hcp4 { font-size:10pt; }
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p.hcp5 { color:#333333;
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font-size:10pt; }
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span.hcp6 { font-weight:bold; }
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h2.hcp7 { font-size:10pt; }
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-->
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</style>
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</head>
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<body>
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<h1 class="firstHeading">Leveller</h1>
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<p><font face="Arial" class="hcp1"><font size="3" class="hcp2"><img src="MAIN0126.gif" alt="MAIN0126.gif" title="MAIN0126.gif" width="137" height="51" border="0" class="hcp3"></font></font></p>
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<p class="hcp4">The leveller will attempt to keep the nominal
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level of the signal close to the desired target level set by the user,
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by gently changing the gain. An intelligent detection algorithm makes
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this processing object very free of side effects and easy to set up.</p>
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<p class="hcp5"><span class="hcp6">Inputs
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and Outputs</span></p>
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<p class="hcp4">One audio input and one audio output.</p>
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<h2 class="hcp7">Properties</h2>
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<p class="hcp4"><span class="hcp6">Voice band
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Filter</span>: Optionally included so that the levelling action favours
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frequencies in the human vocal range, helping to discriminate from noise
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signals.</p>
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<p class="hcp5"><span class="hcp6">Control
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Panel</span></p>
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<p><font face="Arial" class="hcp1"><font size="3" class="hcp2"><span class="hcp6"><img src="MAIN0127.gif" alt="MAIN0127.gif" title="MAIN0127.gif" width="491" height="257" border="0" class="hcp3"></span></font></font></p>
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<p class="hcp4"><span class="hcp6">Target Output</span>
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control<br>
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Adjusts the level which the leveller tries to maintain. The more positive
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the value, the higher the output level will be.</p>
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<p class="hcp4"><span class="hcp6">Ratio</span>
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control<br>
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Adjusts the aggressiveness of levelling. Lower values allow more tolerance;
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allowing the output level to differ more from the target level, which
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preserves more of the original dynamics of the signal at the expense of
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firm control over the level. Higher ratio values cause the output level
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to be more tightly 'driven' towards the target level.</p>
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<p class="hcp4"><span class="hcp6">Maximum Gain</span>
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control<br>
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Determines how much gain the object is allowed to apply to bring a low
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level signal up to the target level. Higher gain values allow the leveller
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to add more gain when the signal level is low, but will also bring up
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the noise floor more.</p>
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<p class="hcp4"><span class="hcp6">Speed</span>
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control<br>
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Adjusts the time it takes for the leveller to recover from high levels
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when low levels are encountered. Higher values make the recovery slower,
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so there are no sudden jumps in gain. Lower (faster) values allow the
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leveller to track and counteract rapidly decreasing levels.</p>
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<p class="hcp4"><span class="hcp6">Bypass</span>
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button<br>
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Removes the leveller from the signal path.<span class="hcp6"><br>
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!</span> WARNING - significant changes in signal level can be caused by
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this control.</p>
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<p class="hcp4"><span class="hcp6">Threshold</span>
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control<br>
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Determines the lowest input level that the Leveller will attempt to correct.
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Correct setting of this control is critical to the leveller's ability
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to discriminate unwanted noise from the wanted signal. Lower values will
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allow the leveller to 'pull-up' lower level signals, but will also make
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it more prone to activate on noise signals. Note that the intelligent
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detection algorithm helps to prevent noise signals from triggering levelling
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action even when they are above the threshold level, (if the leveller
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does not recognise them as vocal signals).</p>
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<p class="hcp4"><span class="hcp6">Active LED</span><br>
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Shows when the intelligent detector is allowing levelling action to take
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place. This is used along with the Threshold control to confirm that noise
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signals do not activate the detector, but wanted signals do.</p>
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<p class="hcp4"><span class="hcp6">Gain meter</span><br>
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Displays how much adjustment the leveller is applying to the signal.</p>
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<h2 class="hcp7">Notes</h2>
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<p class="hcp4"><span class="hcp6">!</span> It
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should be noted that this object is capable of raising signal levels beyond
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the clipping point, so care should be exercised when using large Maximum
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Gain values.</p>
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<p class="hcp4"><span class="hcp6">!</span> It
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is recommended that a Limiter be used on the output of the Leveller so
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that short-term high-level signals (which may not be attenuated by the
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Leveller), are not allowed to pass through to the output.</p>
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<p style="margin-bottom: 0;"><font style="font-size: 10pt;" size="2">An
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expander connected on the input side of the leveller may be useful in
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aiding the leveller to discriminate noise signals from wanted signals</font></p>
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</body>
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</html>
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