<h2>Introduction</h2>
<p>
- An engineer reading and using audio level meters compares to a musician
- reading or writing sheet-music. Just like there are virtuoso musicians
+ An engineer reading and using audio level meters compares to a musician
+ reading or writing sheet-music. Just like there are virtuoso musicians
who can't read a single note, there are great sound-engineers who just
- go by their ears and produce great mixes and masters without ever looking
+ go by their ears and produce great mixes and masters without ever looking
at a single meter.
</p>
<p>
- Yet, if you want to work in or with the broadcast industry, it is
+ Yet, in order to work in or with the broadcast industry, it is
usually unavoidable to use meters.
</p>
<p>
- Audio level meters are very powerful tools that are useful in every
+ Audio level meters are very powerful tools that are useful in every
part of the entire production chain:
</p>
<ul>
- <li>When tracking, meters are used to ensure that the input
- signal does not <dfn>overload</dfn> and maintains reasonable
+ <li>When tracking, meters are used to ensure that the input
+ signal does not <dfn>overload</dfn> and maintains reasonable
<dfn>headroom</dfn>.</li>
- <li>Meters offer a <dfn>quick visual indication</dfn> of a
+ <li>Meters offer a <dfn>quick visual indication</dfn> of an
activity when working with a large number of tracks.</li>
- <li>During mixing, meters provide an rough estimate of the
+ <li>During mixing, meters provide an rough estimate of the
<dfn>loudness</dfn> of each track.</li>
- <li>At the mastering stage, meters are used to check
- compliance with upstream <dfn>level</dfn> and <dfn>loudness
+ <li>At the mastering stage, meters are used to check
+ compliance with upstream <dfn>level</dfn> and <dfn>loudness
standards</dfn> and to optimize the <dfn>loudness range</dfn>
for a given medium.</li>
</ul>
<h2>Meter Types</h2>
<p>
- A general treatise on metering is beyond the scope of this
+ A general treatise on metering is beyond the scope of this
manual. It is a complex subject with a history…
For background information and further reading we recommend:
</p>
<ul>
<li><a href="http://www.digido.com/how-to-make-better-recordings-part-2.html">How To Make Better Recordings in the 21st Century—An Integrated Approach to Metering, Monitoring, and Leveling Practices</a> by Bob Katz. Has a good historic overview of meters and motivates the K-meter</li>
<li><a href="https://en.wikipedia.org/wiki/Peak_programme_meter#Table_of_characteristics">Wikipedia: Peak programme meter</a>—overview of meter types.</li>
- <li>"Audio Metering: Measurements, Standards and Practice: Measurements, Standards and Practics", by Eddy Brixen. ISBN: 0240814673</li>
+ <li>"Audio Metering: Measurements, Standards and Practice: Measurements, Standards and Practice", by Eddy Brixen. ISBN: 0240814673</li>
<li>"Art of Digital Audio", by John Watkinson. ISBN: 0240515870</li>
</ul>
There are different metering standards, most of which are available in Ardour. In short:
</p>
-<dl>
- <dt>Digital peak-meter</dt>
- <dd>A <dfn>Digital Peak Meter</dfn> displays the absolute maximum signal
- of the raw audio PCM signal (for a given time). It is commonly used when
- tracking to make sure the recorded audio never clips. To that end, DPMs
+<table class="dl">
+ <tr><th>Digital peak-meter</th>
+ <td>A <dfn>Digital Peak Meter</dfn> displays the absolute maximum signal
+ of the raw audio PCM signal (for a given time). It is commonly used when
+ tracking to make sure the recorded audio never clips. To that end, DPMs
are always calibrated to 0 <abbr title="DeciBel Full
Scale">dBFS</abbr>, or the maximum level that can be represented digitally
- in a given system. This value has no musical reason whatsoever and depends
- only on the properties of the signal chain or target medium. There are
- conventions for <dfn>fall-off-time</dfn> and <dfn>peak-hold</dfn>, but no
+ in a given system. This value has no musical reason whatsoever and depends
+ only on the properties of the signal chain or target medium. There are
+ conventions for <dfn>fall-off-time</dfn> and <dfn>peak-hold</dfn>, but no
exact specifications.
<p>
- Various conventions for DPM fall-off times and dBFS line-up level can be
- chosen in <kbd class="menu">Edit > Preferences > GUI</kbd>.
+ Various conventions for DPM fall-off times and dBFS line-up level can be
+ chosen in <kbd class="menu">Edit > Preferences > Metering</kbd>.
</p>
- </dd>
+ </td></tr>
- <dt>RMS meters</dt>
- <
dd>An <dfn><abbr title="Root Mean Square">RMS</abbr>-type meter</dfn>
- is an averaging meter that looks at the energy in the signal. It
- provides a general indication of loudness as perceived by humans. Ardour
- features three RMS meters, all of which offer additonal peak indication.
+ <tr><th>RMS meters</th>
+ <
td>An <dfn><abbr title="Root Mean Square">RMS</abbr>-type meter</dfn>
+ is an averaging meter that looks at the energy in the signal. It
+ provides a general indication of loudness as perceived by humans. Ardour
+ features three RMS meters, all of which offer additional peak indication.
<ul>
<li><dfn>K20</dfn>: A meter according to the K-system introduced by Bob
Katz, scale aligned to -20 dBFS, rise/fall times and color schema
<li><dfn>K14</dfn>: Same as K20 with scale aligned to -14 dBFS.</li>
<li><dfn>K12</dfn>: Same as K20 with scale aligned to -12 dBFS (since 3.5.143).</li>
<li><dfn>Peak + RMS</dfn>: standard RMS, customizable via
- <kbd class="menu">Edit > Preferences > GUI > Metering</kbd></li>
+ <kbd class="menu">Edit > Preferences > Metering</kbd></li>
</ul>
- </dd>
+ </td></tr>
- <dt>IEC PPMs</dt>
- <dd><dfn><abbr title="International Electrontechnical Commission">IEC</abbr>-type
- <abbr title="Peak Programme Meters">PPM</abbr>s</dfn> are a mix between DPMs and
- RMS meters, created mainly for the purpose of
+ <tr><th>IEC PPMs</th>
+ <td><dfn><abbr title="International Electrontechnical Commission">IEC</abbr>-type
+ <abbr title="Peak Programme Meters">PPM</abbr>s</dfn> are a mix between DPMs and
+ RMS meters, created mainly for the purpose of
interoperability. Many national and institutional varieties exist (<abbr
title="European Broadcasting Union">EBU</abbr>, <abbr title="British Broadcasting
- Corporation">BBC</abbr>, <abbr title="Deutsche Industrie-Norm">DIN</abbr>).
+ Corporation">BBC</abbr>, <abbr title="Deutsche Industrie-Norm">DIN</abbr>).
<p>
- These loudness and metering standards provide a common point of
- reference which is used by broadcasters in particular so that the
+ These loudness and metering standards provide a common point of
+ reference which is used by broadcasters in particular so that the
interchange of material is uniform across their sphere of influence,
regardless of the equipment used to play it back.
</p>
<p>
For home recording, there is no real need for this level of
- interoperability, and these meters are only strictly required when
- working in or with the broadcast industry. However, IEC-type meters have
- certain characteristics (rise-time, ballistics) that make them useful
+ interoperability, and these meters are only strictly required when
+ working in or with the broadcast industry. However, IEC-type meters have
+ certain characteristics (rise-time, ballistics) that make them useful
outside the context of broadcast.
</p>
<p>
- Their specification is very exact, and consquently, there are no
+ Their specification is very exact, and consequently, there are no
customizable parameters.
</p>
- </dd>
-
- <dt>VU meters</dt>
- <dd><dfn><abbr title="Volume Unit">VU</abbr> meters</dfn> are the dinosaurs (1939)
+ </td></tr>
+
+ <tr><th>VU meters</th>
+ <td><dfn><abbr title="Volume Unit">VU</abbr> meters</dfn> are the dinosaurs (1939)
amongst the meters. They react very slowly, averaging out peaks.
- Their specification is very strict (300ms rise-time, 1–1.5% overshoot,
- flat frequency response). Ardour's VU meter adheres to that spec, but for
+ Their specification is very strict (300ms rise-time, 1–1.5% overshoot,
+ flat frequency response). Ardour's VU meter adheres to that spec, but for
visual consistency it is displayed as a bar-graph rather than needle-style
(more below).
- </dd>
-</dl>
+ </td></tr>
+</table>
<h2>Ardour Specifics</h2>
-<img class="right" src="/images/mixer-meter-context-menu.png" alt="mixer strip meter context menu" />
+<figure class="right">
+ <img src="/images/mixer-meter-context-menu.png" alt="mixer strip meter context menu">
+ <figcaption>
+ Mixer strip meter context menu
+ </figcaption>
+</figure>
+
<p>
- Meters are available in various places in ardour:
+ Meters are available in various places in Ardour:
</p>
<ul>
<li>The mixer window features fixed height meters for each <dfn>channel strip</dfn>.</li>
</ul>
<p>
They all share the same configuration and color-theme which is available in
- preferences and the theme-manager. Settings for the Peak and RMS+Peak meters
- as well as VU meter standards are found in
- <kbd class="menu">Edit > Preferences > GUI > Metering</kbd>.
+ preferences and the theme-manager. Settings for the Peak and RMS+Peak meters
+ as well as VU meter standards are found in
+ <kbd class="menu">Edit > Preferences > Metering</kbd>.
</p>
+
<p>
The type of meter and the <dfn>metering point</dfn> (the place in the signal chain
where the meter taps the signal) are configurable in the context menu of each meter.
- Depending on the <kbd class="menu">Edit > Preferences > GUI > Mixer
- Strip</kbd> settings, the metering point is also accessible via a button in
- each Mixer strip.
+ Depending on the <kbd class="menu">Edit > Preferences > Mixer</kbd> settings,
+ the metering point is also accessible via a button in each Mixer strip.
</p>
-<img class="right" src="/images/meter-preferences.png" alt="" />
+
<p>
- Regardless of meter type and standard the meter display will highlight red if
+ Regardless of meter type and standard the meter display will highlight red if
the signal on the given channel exceeds the configured peak threshold.
</p>
<p>
- <kbd class="mouse">Left</kbd> on the peak-indicator button resets the
+ <kbd class="mouse">Left</kbd> clicking on the peak-indicator button resets the
<dfn>peak-hold indicator</dfn> of a single channel.<br>
- <kbd class="mod1 mouse">Left</kbd> resets a whole <dfn>group</dfn>, and<br/>
- <kbd class="mod13 mouse">Left</kbd> resets all meters.
+ <kbd class="mod1 mouse">Left</kbd> clicking resets a whole <dfn>group</dfn>, and<br/>
+ <kbd class="mod13 mouse">Left</kbd> clicking resets all meters.
</p>
<h2>Overview of meter types</h2>
+<figure class="left">
+ <img class="mini" src="/images/meter-types-18.png" alt="Bar-graph meters in Ardour">
+ <figcaption>
+ Bar-graph meters in Ardour
+ </figcaption>
+</figure>
+
+<figure class="right">
+ <img class="mini" src="/images/needle-meters-18.png" alt="Needle-style meters as external LV2 plugins">
+ <figcaption>
+ Needle-style meters as external LV2 plugins
+ </figcaption>
+</figure>
+
<p>
- The figure on the left shows all available meter-types in Ardour 3.4 when fed with a
+ The figure on the left shows all available meter-types in Ardour when fed with a
-18 dBFS 1 kHz sine wave.
</p>
-<img class="right" style="max-width:45%;height:400px;" src="/images/needle-meters-18.png"
-alt="Needle-style meters as external LV2 plugins" />
-<img style="max-width:45%; height:400px" src="/images/meter-types-18.png"
-alt="Bar-graph meters in Ardour" />
-
<p>
- Due to layout concerns and consistent look&feel all meters available in
+ Due to layout concerns and consistent look and feel all meters available in
Ardour itself are bar-graph type meters. Corresponding needle-style
meters—which take up more visual screen space—are available as
LV2 plugins (see image on the right):
<a href="https://github.com/x42/meters.lv2/">meters.lv2</a>.
</p>
-
projects / ardour-manual / blobdiff