manual/include/aux-sends.html

<p>
  <dfn>Auxiliary sends</dfn> are simple <a
  href="@@processor-box">processors</a> in a bus or
  track channel strip. They tap the signal at a specific point in the signal
  flow (pre-fader, post-fader, before or after EQs and other plugins, etc.)
  and send a copy of that signal to a bus, without affecting the
  normal signal flow downwards to the channel fader.
</p>
<p>
  Aux sends from several tracks are collectively sent to a
  <dfn>bus</dfn> in Ardour, to create a monitor mix for a
  musician, or to feed an effect unit. A bus used in this way is considered
  an auxiliary bus or <dfn>Aux bus</dfn> even though it is the same as
  any other bus. The output of such a bus might
  be routed to separate hardware outputs (in the case of headphone or monitor
  wedge mixes), or returned to the main mix (in the case of an effect).
</p>
<p>
  Aux sends do not show up outside of Ardour either on the audio device
  or as JACK ports, <a href="@@external-sends">External Sends</a> should
  be used to send audio to the audio device or Jack ports. External Sends can
  send the tapped signal somewhere else directly, which is not usually
  possible on hardware mixers.
</p>

<p>
  It may be useful to
  <a href="@@comparing-aux-sends-and-subgroups">compare and contrast</a>
  the use of aux sends with <a href="@@subgrouping">subgrouping</a>.
</p>

<h2>Adding a new aux bus</h2>
<p>
  New busses can be created using the <kbd class="menu">Session &gt; Add Track, Bus or VCA&hellip;</kbd>
  menu, and selecting <kbd class="menu">Audio Busses</kbd> in the Template/Type
  selector on the left of the <kbd class="menu">Add Track/Bus/VCA</kbd> dialog.
</p>

<h2>Adding a send to an aux bus</h2>
<p>
  Context-clicking on the processor box for the track to send to the bus, and
  choosing <kbd class="menu">New Aux Send &hellip;</kbd> shows a submenu, listing the busses.
  Choosing one bus will add a send (which will be visible in the processor box).
  Note that if the only existing bus is the Master Bus, the menu will be grayed out.
</p>

<h3>Pre-fader and Post-fader Aux Sends</h3>
<p>
  Depending on whether the context-click happened above or below the fader in the
processor box, the new aux send can be placed before or after the fader in the
channel strip.
</p>
<ul>
  <li><dfn>Post-fader</dfn> aux sends are typically used when using an aux for
  shared signal processing (FX), so that the amount of effect is always
  proportional to the main mix fader.</li>
  <li><dfn>Pre-fader</dfn> sends ensure
  that the level sent to the bus is controlled <em>only</em> by the send, not the
  main fader&mdash;this is typical when constructing headphone and monitor wedge
  mixes.</li>
</ul>

<p>
    The color of the processor will reflect this pre/post position (red for
    <span class="for-red">Pre</span>, green for <span
    class="for-green">Post</span>). Dragging and dropping the send inside
    the processor box before or after the Fader processor changes the type of
    fader accordingly.
</p>


<h2>Adding a new aux bus and sending a Track Group to it</h2>
<p>
  All members of a group can be sent to a new aux bus at once with a single click.
  After creating the <a href="@@track-and-bus-groups">track group</a>
  (and adding tracks to it), context-clicking on the group tab allows to choose either
  <kbd class="menu">Add New Aux Bus (pre-fader)</kbd> or
  <kbd class="menu">Add New Aux Bus (post-fader)</kbd>. A new aux bus will be created,
  and a new aux send added to every member of the track group that connects to
  this aux bus.
</p>

<h2>Altering Send Levels</h2>
<p>
  The amount of the signal received by a send that it delivers to the bus it connects to
  can be altered in two ways:
</p>
<h3>Using the Send Fader</h3>
<p>
  Every send processor has a small horizontal fader that can be adjusted in the
usual way. It is not very big and so this can be a little unsatisfactory if
a very fine control over the send level is required.
</p>
<h3>Map Aux Sends To Main Faders</h3>
<p>
  In Mixer mode, pressing the button marked <kbd class="menu">Show Sends</kbd> on a aux bus will
  alter the channel strip for every track or bus that feeds the aux bus. Many
  aspects of the strip will become insensitive and/or change their visual
  appearance. More importantly, the main fader of the affected channel strips
  will now control the send level and <strong>not</strong> the track gain.
  This gives a larger, more configurable control to alter the level. Clicking the
  <kbd class="menu">Show Sends</kbd> button of the aux bus again reverts the
  channel strips to their normal use.
</p>

<h2>Disabling Sends</h2>
<p>
  Clicking on the small LED in the send display in the processor box of the
  channel strip will enable/disable the send. When disabled, only silence will
  be delivered to the aux bus by this track. When enabled, the signal arriving
  at the send will be delivered to the aux bus.
</p>

<h2>Send Panning</h2>
<p>
  Send panners can be configured to either be independent of the main
  panner, or to follow it. The latter could be useful for Reverb effects, or
  for in-ear monitor mixes delivered in stereo.
</p>