manual/include/bundled-plugins-filters.html

<h2>ACE Compressor</h2>

<p>
  The job of this filter is to make an audio recording perceivably louder by
  reducing the dynamic range, that is, the difference between the loudest and
  the quietest parts. ACE compressor lowers the volume of loud sounds above a
  user-defined threshold measured in dB, then the gain of all the sound gets
  increased to make up for lost loudness.
</p>

<figure>
  <img style="width:50%;" src="/images/a-compressor.png" alt="ACE Compressor">
  <figcaption>
    ACE Compressor
  </figcaption>
</figure>

<p>Available settings are:</p>

<ul>
<li><strong>Threshold</strong>. This setting defines the loudness at which the compressor
will start working.</li>
<li><strong>Knee</strong>. Whether the transition from uncompressed to compressed is soft
or hard. The effect is more noticeable with larger ratios.</li>
<li><strong>Ratio</strong>. How much the gain is reduced above a certain threshold.
If the ratio is e.g. 5:1, 5dB will become 1dB.</li>
<li><strong>Attack</strong>. How long (in ms) it takes to apply maximum compression.</li>
<li><strong>Release</strong>. How long it takes to return to zero compression.</li>
<li><strong>Makeup Gain</strong>. How much the overall level should be increased after
reducing loud sections.</li>
<li><strong>Sidechain</strong>. Whether the effect should be activate by the loadness
of audio signal in another track passing a certain threshold.</li>
</ul>
<p>The plugin also provides an opt-out inline display that shows input signal,
threshold, and resulting gain reduction:</p>

<figure>
  <img style="width:75%;" src="/images/a-compressor-inline.png" alt="Inline ACE Compressor display">
  <figcaption>
    Inline display
  </figcaption>
</figure>

<h2>ACE Expander</h2>

<p>
  Contrary to compressors, expanders increase the dynamic range either
  by making quite sounds quieter (downward expanders) or by making loud
  sounds louder (upward expanders). <em>ACE Expander</em> is a downward
  expander. It reduces the level of a signal below a user-defined threshold
  by user-defined ratio, then optionally increases the overall gain to make
  up for lost loudness.
</p>

<figure>
  <img style="width:50%;" src="/images/a-expander.png" alt="ACE Expander">
  <figcaption>
    ACE Expander
  </figcaption>
</figure>

<p>Available settings are:</p>

<ul>
  <li><strong>Attack</strong>. How long (in ms) it takes to apply maximum
  reduction of the quiet sections.</li>
  <li><strong>Release</strong>. How long it takes to stop reducing the quiet
  signal at all.</li>
  <li><strong>Knee</strong>. Whether the transition from non-reduced to
  reduced signal level is soft or hard. The effect is more noticeable with
  larger ratios.</li>
  <li><strong>Ratio</strong>. How much the gain is reduced below a certain
  threshold. If the ratio is e.g. 3:1, -10dB will become -30dB.</li>
  <li><strong>Threshold</strong>. The loudness at which the expander will
  start working.</li>
  <li><strong>Makeup Gain</strong>. How much the overall level should be
  increased after reducing quiet sections.</li>
  <li><strong>Sidechain</strong>. Whether the effect should be activated by
  the loudness of audio signal in another track passing a certain threshold.</li>
</ul>

<p>
  <em>ACE Expander</em> also comes with an inline widget for mixer channels
  that displays the input signal level, the threshold, and the amount of
  reduced signal.
</p>

<figure>
  <img style="width:75%;" src="/images/a-expander-inline.png" alt="Inline ACE Expander display">
  <figcaption>
    Inline display
  </figcaption>
</figure>

<h2>ACE Delay</h2>

<p>
  Delay effects repeat original signal after a user-defined interval.
  In <em>ACE Delay</em>, the interval is calculated from the tempo and the
  divisor&nbsp;&mdash; a musical time unit like a 1/4th note or a dotted 1/16th note.
  When using a delay in music production, it's usually best to sync to
  project's tempo, especially if there are tempo ramps in a song.
</p>

<figure>
  <img style="width:50%;" src="/images/a-delay.png" alt="ACE Delay">
  <figcaption>
    ACE Delay
  </figcaption>
</figure>

<p>Available settings are:</p>

<ul>
  <li><strong>Tempo</strong>. Amount of beats per minute.</li>
  <li><strong>Sync</strong>. This toggles the syncing to project&#39;s
  tempo.</li>
  <li><strong>Divisor</strong>. The interval between the original sound and
  its delayed copy, expressed in whole or fractional notes
  (1/4th, 1/8th etc.)</li>
  <li><strong>Dotted</strong>. When enabled, adds half the divisor unit
  to the delay interval, e.g. a 1/8th note becomes a dotted 1/8th note.</li>
  <li><strong>Time</strong>. The final delay time expressed in milliseconds.</li>
  <li><strong>Feedback</strong>. How much of the processed signal goes back
  into the delay effect&#39;s input.</li>
  <li><strong>Low-Pass Filter (LPF)</strong>. This helps simulating analog
  delay effects where the repeated signal gets dull.</li>
  <li><strong>Invert</strong>. This option inverts the polarity of the output
  signal.</li>
  <li><strong>Output Gain</strong>. Reduces or increases the level of the
  output signal.</li>
</ul>

<h2>ACE Reverb</h2>

<p>A reverb effect emulates sound waves reflecting off the walls in a closed
space which could be a a small room or a cathedral. The effect is usually
applied to a &quot;dry&quot; audio recording, that is, one typically made in a
very small room with acoustic absorption treatment so that there are little-to-no
reflections. That way, a reverb effect makes the most sense as it gives you a
clean slate and more freedom to shape your sound.</p>

<p>The <em>ACE Reverb</em> effect is a very simple one, based on early research to
artificial reverberation by Manfred Schroeder and Ben Logan (<a href="https://ccrma.stanford.edu/~jos/pasp/Schroeder_Reverberators.html">see
here</a> for technical details). There are just two controls:</p>

<ul>
  <li><strong>Blend</strong>. This control changes the mix in favour
  of either &quot;dry&quot; unprocessed signal that is being fed into the
  effect or the &quot;wet&quot; processed by the effect. 0 means you only
  hear the unprocessed signal, 1 mean you only hear the processed signal.</li>
  <li><strong>Room Size</strong>. This control changes the size of the virtual
  room and therefore the amount of decay.</li>
</ul>

<h2 id="ace-high-low-pass-filter">ACE High/Low Pass Filter</h2>

<p>
  High-pass and low-pass filters reduce the signal below and above a certain
  frequency respectively. The <em>ACE High/Low Pass</em> filter combines the
  two filters in one.
</p>

<figure>
  <img style="width:50%;" src="/images/a-lpf-hpf.png" alt="Inline ACE High/Low Pass Filter display">
  <figcaption>
    ACE High/Low Pass Filter
  </figcaption>
</figure>

<p>Each of the two bandpass filters has three controls:</p>

<ul>
  <li><strong>Steepness</strong>. How much the filter reduces the signal per
  each step (12dB/oct to 48dB/oct). Setting steepness to <em>Off</em>
  disables the filter entirely.</li>
  <li><strong>Cutoff frequency</strong>. The base frequency where the filter
  begins cutting off the data.</li>
  <li><strong>Resonance</strong>. How much the signal around the cutoff
  frequency is suppressed (lower values) or emphasized (higher values).
  The plugins defaults to 0.707 which roughly translates to "do nothing".</li>
</ul>

<p>
  The plugin also comes with an inline display visualizing the effect that
  the filters have.
</p>

<figure>
  <img style="width:75%;" src="/images/a-lpf-hpf-inline.png" alt="Inline ACE High/Low Pass Filter display">
  <figcaption>
    Inline display
  </figcaption>
</figure>