manual/include/processor-box.html

<p>
  In Ardour terminology, a <dfn>processor</dfn> is anything which treats the
  signal in some way and gets plugged into a mixer strip. 
  Ardour provides several builtin processors such as the fader or panners.
  Processors can also be <dfn>plugins</dfn> used for effects or as instruments, as well 
  as sends or inserts which are affect <a href="/signal-routing/">signal
  routing</a>.<br>
  The arrangement of processors is arbitrary, and there is no limit to how 
  many there can be.
</p>
<p>
  The main box in the top half of a mixer strip shows the <dfn>processor
  box</dfn>. 
  Processors are shown as coloured rectangles, with a small "LED" beside 
  them that lights up when the processor is enabled. The colour of the 
  processor depends on its location in the sequence; processors that are <dfn>pre-fader</dfn> are 
  coloured in red, and <dfn>post-fader</dfn> processors are coloured green 
  (in the default theme).</p>
<p>
  The processor box will always contain a blue <dfn>Fader</dfn> processor. 
  This indicates where in the processor chain the main channel fader is 
  located&mdash;this is the fader shown in the lower half of the strip.
</p>
<h2>Adding Processors</h2>
<p>
  Processors can be added to the chain by 
  <kbd class="mouse">Right</kbd>-clicking in the processor list, This does three things:
</p>
<ul>
  <li>A gap is opened up to indicate the location of the click. The gap 
  shows where any new processors will be inserted.</li>
  <li>The processor under the click is selected.</li>
  <li>An options  menu is presented.</li>
</ul>
<p>
  From the menu, new processors can be inserted.
</p>

<h2>To Reorder (Move) Processors</h2>
<p>
  Processors can be re-ordered using drag-and-drop. Dragging a processor 
  allows it to be moved around within the chain, or copied to another 
  processor list on another track or bus.
</p>

<h2>To Enable/Disable a Processor</h2>
<p>
  To the left of the name of each processor is a small LED symbol; if this 
  is lit-up, the processor is active. Clicking on it will deactivate the
  processor and effectively bypass it.</p>
  
<h2>Removing Processors</h2>
<p>
  Context-click on the processor you want to remove, and select <kbd
  class="menu">Delete</kbd>, or <kbd class="mod3 mouse">Right</kbd>-click on it. 
</p>