---
<p>
- The default stereo panner distributes two inputs to two outputs. Its
- behaviour is controlled by two parameters, <strong>width</strong> and
- <strong>position</strong>. The
- default settings for the stereo panner are <em>width=100%</em> and
- <em>position=center</em>.
- This stereo panner assumes that the signals
+ The default <dfn>stereo panner</dfn> distributes two inputs to two outputs. Its
+ behaviour is controlled by two parameters, <dfn>width</dfn> and
+ <dfn>position</dfn>. By default, the panner is centered at full width.
+</p>
+<p>
+ The stereo panner assumes that the signals
you wish to distribute are either uncorrelated (i.e. totally
independent), or that they contain a stereo image which is
- <em>mono-compatible</em>, such as a co-incident microphone recording, or a
+ <dfn>mono-compatible</dfn>, such as a co-incident microphone recording, or a
sound stage that has been created with pan pots.<sup><a href="#caveat">*</a></sup>
</p>
-<div class="well">
+<p class="note">
With the default values it is not possible to alter the position,
since the width is already spread entirely across both outputs. To
alter the position, you must first reduce the width.
-</div>
+</p>
<h2>Stereo Panner User Interface</h2>
<img src="/images/stereo-panner-annotated.png" alt=""/>
-
<p>
- The panner user interface consists of three elements, divided between
+ The <dfn>panner user interface</dfn> consists of three elements, divided between
the top and bottom half. Click and/or drag in the top half to
control position; click and/or drag in the bottom half to control
width (see below for details).
<p>
Although the implementation of the panner uses the "position"
- parameter, when the user interface displays it numerically, it shows a pair of numbers that
- will be familiar to most audio engineers.
+ parameter, when the user interface displays it numerically, it shows
+ a pair of numbers that will be familiar to most audio engineers.
</p>
<table>
To change the position smoothly, press the right button and drag
within the top half of the panner, then release. The position will
be limited by the current width setting. <em>Note: you do not need
- to grab the position indicator in order to drag</em>
+ to grab the position indicator in order to drag.</em>
</p>
<p>
To change the width smoothly, press the right button and drag
within the lower half of the panner, then release. The width will be
- limited by the current position setting.<em>Note: you do not need to
- grab the L/R indicators in order to drag</em>
+ limited by the current position setting. <em>Note: you do not need to
+ grab the L/R indicators in order to drag.</em>
</p>
<dl class="faq">
<dt>Reset to defaults</dt>
-<dd>Click <kbd class="mod3">right button</kbd></dd>
+<dd>Click <kbd class="mod3 mouse">right</kbd></dd>
-<dt>Change to a "hard left"</dt>
-<dd>Double click <kbd class="mod2">right button</kbd> in the upper left half
+<dt>Change to hard left</dt>
+<dd>Double click <kbd class="mod2 mouse">right</kbd> in the upper left half
of the panner</dd>
-<dt>Change to a "hard right"</dt>
-<dd>Double click <kbd class="mod2">right button</kbd> in the upper right half
+<dt>Change to a hard right</dt>
+<dd>Double click <kbd class="mod2 mouse">right</kbd> in the upper right half
of the panner</dd>
<dt>Move position as far left as possible, given width</dt>
-<dd>Double click <kbd>right button</kbd> in the upper left half of the
+<dd>Double click <kbd class="mouse">right</kbd> in the upper left half of the
panner</dd>
<dt>Move position as far right as possible, given width</dt>
-<dd>Double click <kbd>right button</kbd> in the upper right half of the
+<dd>Double click <kbd class="mouse">right</kbd> in the upper right half of the
panner</dd>
<dt>Set the position to center</dt>
-<dd>Click <kbd>right button</kbd> in the upper middle of the panner</dd>
+<dd>Click <kbd class="mouse">right</kbd> in the upper middle of the panner</dd>
<dt>Reset to maximum possible width</dt>
-<dd>Double click <kbd>right button</kbd> on the lower left side</dd>
+<dd>Double click <kbd class="mouse">right</kbd> on the lower left side</dd>
<dt>Invert (flip channel assignments)</dt>
-<dd>Double click <kbd>right button</kbd> on the lower right side</dd>
+<dd>Double click <kbd class="mouse">right</kbd> on the lower right side</dd>
<dt>Set width to 0°</dt>
-<dd>Double click <kbd>right button</kbd> in the lower middle</dd>
+<dd>Double click <kbd class="mouse">right</kbd> in the lower middle</dd>
</dl>
<h4>Keyboard bindings</h4>
</p>
<dl>
-<dt>left / <kbd class="mod1">left</kbd></dt>
-<dd>increase width by 1° / 5°</dd>
-
-<dt>right / <kbd class="mod1">right</kbd></dt>
-<dd>decrease width by 1° / 5°</dd>
-
-<dt>up / <kbd class="mod1">up</kbd></dt>
-<dd>move position 1° / 5° to the left</dd>
-
-<dt>down / <kbd class="mod1">down</kbd></dt>
-<dd>move position 1° / 5°to the right</dd>
+ <dt><kbd class="mouse">⇐</kbd> / <kbd class="mod1 mouse">⇐</kbd></dt>
+ <dd>increase width by 1° / 5°</dd>
+ <dt><kbd class="mouse">⇒</kbd> / <kbd class="mod1 mouse">⇒</kbd></dt>
+ <dd>decrease width by 1° / 5°</dd>
+ <dt><kbd class="mouse">⇑</kbd> / <kbd class="mod1 mouse">⇑</kbd></dt>
+ <dd>move position 1° / 5° to the left</dd>
+ <dt><kbd class="mouse">⇓</kbd> / <kbd class="mod1 mouse">⇓</kbd></dt>
+ <dd>move position 1° / 5°to the right</dd>
</dl>
<h2><a name="caveat"></a>Stereo panning caveats</h2>
-<div class="well">
+<p class="warning">
The stereo panner will introduce unwanted side effects on
material that includes a time difference between the channels, such
as A/B, ORTF or NOS microphone recordings, or delay-panned mixes.<br />
When you reduce the with, you are effectively summing two highly
-correlated signals with a delay, which will cause comb filtering.
-</div>
+correlated signals with a delay, which will cause <dfn>comb filtering</dfn>.
+</p>
<p>
Let's take a closer look at what happens when you record a source at 45° to the
right side with an ORTF stereo microphone array and then manipulate the width.
</p>
<p>
-For testing, we apply a pink noise signal to both inputs of an Ardour stereo
+For testing, we apply a <dfn>pink noise</dfn> signal to both inputs of an Ardour stereo
bus with the stereo panner, and feed the bus output to a two-channel analyser.
Since pink noise contains equal energy per octave, the expected readout is a
straight line, which would indicate that our signal chain does not color the
analyser.
</p>
<p>
-Recall that an ORTF microphone pair consists of two cardioids spaced 17 cm
+Recall that an <dfn>ORTF</dfn> microphone pair consists of two cardioids spaced 17 cm
apart, with an opening angle of 110°.
For a far source at 45° to the right, the time difference between the capsules
is 350 μs or approximately 15 samples at 44.1 kHz. The level difference
no longer be able to sort out the timbral mess. As usual, you
get to keep the pieces.
</p>
-<div class="well">
+<p class="note">
Depending on your material and on how much you need to manipulate the width,
some degree of comb filtering may be acceptable. Then again, it may not. Listen
carefully for artefacts if you manipulate unknown stereo signals — many
orchestra sample libraries for example do contain time-delay components.
-</div>
+</p>
+
projects / ardour-manual-diverged / blobdiff