Effect Menu

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  • Peter 13Dec14: ToDo-2 This page is now getting *very* long - to the point of TLDR and making it hard to navigate. At the very least it would benefit from a custom TOC - or we could consider breaking it up placing some of the detail on sub-pages - or even both. Thoughts ...
  • Bill 13Dec2014: No kidding! Let's try the TOC to start with. As for moving stuff off this page, I can see moving Real-time Preview to its own page (which would need fleshing out with examples to make it worth while) and moving Register Plugins to Effects Preferences.
  • Peter 15Dec14: Ok Bill, I've tried out a Custom TOC (replacing in the process the old "Effect Classes" H2 section).

    I would strongly support moving the RTP to its own page as this would give you the benefit of being able to link to that page far any effect that supports RTP.

    I would strongly vote for also hiving off LV2, VST and Audio Unit sections onto their own pages, particularly as none of them has pre-supplied effects included with Audacity.

    • Bill 15Dec2014: I've moved the Register Plugins diaanagelog to the Effects Preferences page. We'll see if the other editors like that. I've removed the "Install VST Plugins" section from this page (it's obsolete anyway, and most of it still exists on the Effects Preferences page).

      By all means hive off those four sections and we'll see how it looks. I assume you'll save this page in its current state somehow just in case everyone hates the separate pages. ;-)

    • Peter 16Dec14:Bill, I've hived off your RTP to its own page - no-one can really object to this (apart from you as the very recent creator of the page. I added links on this page to the new FTP page. I think this page looks better without the RTP material on it, especially at the top of the page. And looking at this page as it stands now with the custom TOC - I can't decide whether we should also be hiving off the LV2, VST and Audio Unit sections to their own pages. I'm minded to do so because the average user will never see such things in the Effect menu. But the page appears (to me at least) readable and navigable in spite of its length.

Menu Effets Menú Efecto Effektmenü


Audacity includes many built-in effects and also lets you use a wide range of plugin effects. You can download many free plugins for Audacity from http://audacity.sourceforge.net/download/plugins

To apply an effect, select part or all of the tracks you want to modify, and select the effect from the menu. Titles which end in an ellipsis (...) will bring up a dialog asking you for more parameters.

Some types of effects in Audacity support real-time preview. These are: LADSPA, VST, and Audio Unit.

Although by default, the only effects shortcut is CTRL + R to repeat the last used effect, it is possible to set up your own shortcut for any effect in the menu. For instructions on how to do this please see Keyboard Preferences.
Warning icon When playing, recording or paused, effects in the Effect menu that do not support real-time preview will appear grayed out, because changes to the audio data cannot be made until you press the yellow Stop The Stop button button .

Contents

Where a Built-in or shipped Nyquist effect has settings, its description page (accessed by the links below) shows an image of the interface and its default settings.

Built-in Effects

Audacity's built-in effects (those that appear in the program irrespective of the contents of your Audacity and other "Plug-Ins" folders) are above the divider in the Effect menu.

Most of the built-in effects (and most Nyquist effect plugins shipped with Audacity) have a Preview button. This allows you to listen to how the first six seconds (by default) of the selected audio would sound if you pressed OK to apply the effect. The preview length can be changed on the Playback tab of Preferences.

All selected tracks are previewed irrespective of whether the tracks are muted or soloed. This is because the effect is applied to the selected audio. If Preview does not sound quite as you want, adjust the controls of the effect and Preview again.

Built-in effects do not support real-time preview.

Amplify...

Increases or decreases the volume of the audio you have selected. When you open the dialog, Audacity automatically calculates the maximum amount you could amplify the selected audio without causing clipping (distortion caused by trying to make the audio too loud).

Auto Duck...

Reduces (ducks) the volume of one or more tracks whenever the volume of a specified "control" track reaches a particular level. Typically used to make a music track softer whenever speech in a commentary track is heard.

Bass and Treble...

Increases or decreases the lower frequencies and higher frequencies of your audio independently. It behaves just like the bass and treble controls on a domestic stereo system.

Change Pitch...

Change the pitch of a track without changing its tempo.

Change Speed...

Change the speed of a track, also changing its pitch.

Change Tempo...

Change the tempo of a selection without changing its pitch.

Peter 23Jul14: Classic Filters marked as "experimental" and removed from 2.0.6

Classic Filters...

Provides three different types of filters which together emulate the vast majority of analog filters, and provides useful tools for analysis and measurement.

Click Removal...

Click Removal is designed to remove clicks on audio tracks and is especially suited to declicking recordings made from vinyl records. It will usually work best on very short clicks. For broader individual pops in selections up to 128 samples wide (about three milliseconds at 44100 Hz project rate), you could try the Repair effect.

Compressor...

Compresses the dynamic range by two alternative methods. The default "RMS" method makes the louder parts softer, but leaves the quieter audio alone. The alternative "peaks" method makes the entire audio louder, but amplifies the louder parts less than the quieter parts. Make-up gain can be applied to either method, making the result as loud as possible without clipping, but not changing the dynamic range further.

Echo...

Repeats the selected audio again and again, normally softer each time. The delay time between each repeat is fixed, with no pause in between each repeat. For a more configurable echo effect with a variable delay time and pitch-changed echoes, see Delay...

Equalization...

Adjusts the volume levels of particular frequencies.

Fade In

Applies a fade-in to the selected audio, so that the amplitude changes gradually from silence at the start of the selection to the original amplitude at the end of the selection. The shape of the fade is linear. The rapidity of the fade-in depends entirely on the length of the selection it is applied to.

Fade Out

Applies a fade-out to the selected audio, so that the amplitude changes gradually from the original amplitude at the start of the selection down to silence at the end of the selection. The shape of the fade is linear. The rapidity of the fade-out depends entirely on the length of the selection it is applied to.

Invert

Flips the audio samples upside-down. This normally does not affect the sound of the audio at all. It is occasionally useful for vocal removal.

Leveler...

Bill 09Apr12: Add link to Leveler page once that page has some content on it.
  • Bill 27Aug2012: I would hope that the Leveler will soon be dropped from Audacity. If I understand the history correctly, this was added for use with CleanSpeech at a quick and dirty (very dirty!) compressor that could be used in a chain. It introduces unacceptable distortion (IMO) when used as a compressor. It has some (very limited) use as a "distorted vocal" effect. So, I'd rather lobby for its removal rather than spend more time documenting it.
    • Peter 5Nov12: I see no rush to remove "Leveler" from the Audacity repertoire - so I went ahead and documented this effect notwithstanding Bill's comments. And I added the link as Bill had suggested.
    • Gale 10Nov12: I agree, while it's there which I think it will probably be for some time, it ought to be documented. BTW with fairly quiet audio with good dynamic range, most settings do not make the loud parts quieter, just increase them a little less, so I changed that text.

Leveler is a simple, combined compressor and limiter effect for reducing the dynamic range of audio. It reduces the difference between loud and soft, making the audio easier to hear in noisy environments or on small loudspeakers. It is best suited to speech recordings but at heavier settings or used multiple times it can also be used as a simple distortion effect for voices or instruments.

Peter 09Dec14: The new Noise Reduction effect replaces Noise Reduction in 2.1.0 and Noise Reduction effect will be "retired".

  • Bill 13Dec2014: Yes, we brought in Rick Deckard to deal with Noise Removal. I'll be writing the new page "real soon now". New Noise Reduction page now under construction.

Noise Removal...

Removes constant background noise such as fans, tape noise, or hums. It will not work very well for removing talking or music in the background. More details here.

Noise Reduction...

Reduces constant background noise such as fans, tape noise, or hums. It will not work for removing talking or music in the background.

Normalize...

Use the Normalize effect to set the maximum amplitude of a track, equalize the amplitudes of the left and right channels of a stereo track and optionally remove any DC Offset from the track.

Nyquist Prompt...

Launches a dialog where you can enter Nyquist commands. Nyquist is a programming language for producing and processing audio. For more information see Nyquist Plugins Reference.

Paulstretch...

Use Paulstretch only for an extreme time-stretch or "stasis" effect. This may be useful for synthesizer pad sounds, identifying performance glitches or just creating interesting aural textures. Use Change Tempo or Sliding Time Scale rather than Paulstretch for tasks like slowing down a song to a "practice" tempo.

Phaser...

The name "Phaser" comes from "Phase Shifter", because it works by combining phase-shifted signals with the original signal. The movement of the phase-shifted signals is controlled using a Low Frequency Oscillator (LFO).

Repair

Fix one particular short click, pop or other glitch no more than 128 samples long.

Repeat...

Repeats the selection the specified number of times.

Reverb...

Adds ambience or a "hall effect".

Reverse

Reverses the selected audio, so that it will sound as if it is playing from the end to the start.

Sliding Time Scale / Pitch Shift...

Allows you to make a continuous change to the tempo and/or pitch of a selection by choosing initial and/or final change values.

Time Tracks can be used to bend tempo more flexibly (also affecting pitch) using Envelope Tool.

Truncate Silence...

Automatically try to find and eliminate audible silences. Don't use with faded audio.

Wahwah...

Rapid tone quality variations, like that guitar sound so popular in the 1970's.

Wahwah uses a moving bandpass filter to create its sound. A low frequency oscillator (LFO) is used to control the movement of the filter throughout the frequency spectrum.

The phase of the left and right channels is automatically adjusted when given a stereo track, so that the effect seems to travel across the speakers.

The following five types of effect always appear underneath the divider in the Effect menu. Released builds of Audacity include sample Nyquist and/or LADSPA effects.

Nyquist Effects

ToDo Not a priority for 2.1, but needs a little more here:
  • where to get docs
  • the debug button in Nyquist effects
Nyquist effects do not support real-time preview.

Nyquist plugins provide most of the optional effects underneath the divider in the Effect menu. They are also used to provide some of Audacity's built-in audio generators and analysis tools. A wide range of additional Nyquist effect, generation and analysis plugins can be obtained from Download Nyquist Plugins on our Wiki.

To add a Nyquist plugin, put it in the Audacity "Plug-Ins" folder.
  • On Windows and OS X the "Plug-Ins" folder is in the directory where Audacity resides - usually C:\Program Files on Windows or the "Applications" folder on OS X.
  • On Linux, the "plug-ins" folder is in usr/share/audacity if you installed an Audacity package supplied by your distribution, or usr/local/share/audacity if you compiled Audacity from source code. Optionally a "plug-in" folder can be created in the home directory ~/.audacity-files/plug-ins.
The next time you launch Audacity, plugins you added will appear in the Effect, Generate or Analyze menus as appropriate.

Nyquist Workbench

For advanced users who can compile Audacity, Nyquist Workbench gives the ability to run arbitrary Nyquist code in Audacity from a graphical IDE (Integrated Development Environment). See Nyquist Workbench in the Wiki for details.

Nyquist plugins included in Audacity

The following sample Nyquist plugins are included in released builds of Audacity:

Adjustable Fade...

Launches a dialog box where you can choose the shape of the fade in or fade out to be applied. You can also create fades to and from other than silence or full volume. An example of this might be a fade in from 20% of the original volume to 80% of the original volume.

Clip Fix...

Attempts to reconstruct clipped regions by interpolating the lost signal.

Crossfade Tracks

Applies a crossfade to a selected region of a pair of tracks.

Delay...

A configurable delay effect with variable delay time and pitch shifting of the delays.

High Pass Filter...

Passes frequencies above its cutoff frequency and attenuates frequencies below its cutoff frequency; this can be used to reduce low frequency noise.

Low Pass Filter...

Passes frequencies below its cutoff frequency and attenuates frequencies above its cutoff frequency; this can be used to reduce high pitched noise.

Notch Filter...

Greatly attenuate ("notch out") a narrow frequency band. This is a good way to reduce mains hum or a whistle confined to a specific frequency with minimal damage to the remainder of the audio.

Gale 27Oct14:

* The Spectral edit multi-tool GUI (and the other two tools) do not observe the specified Low Frequency and High Frequency values when there is no frequency selection. They just return "Please select frequencies". This may or may not be fixed for next release but the below text can be used when fixed.

  • Why does Spectral edit multi tool and shelves now insist on specifying the Low and High Frequency, whereas as per Spectral Selection this was not previously required?
  • Bill 11Dec2014:
    • The spectral effects no longer function when the track is in waveform view, instead they show an error message. The note below has been edited to reflect this.
    • The dialogs no longer show the high-frequency and low-frequency options. New images now in place.
    • Would it not make more sense for the note below to reference the spectral editing page instead of the spectrogram view on the track drop-down menu page?
    • I've added links back to the spectral selection page for details on the three effects, but I think we be better off with a separate page for each effect so we could get into the details of things like bandwidth, band cut, band boost, shelf filters, etc.
  • Bill 19Dec2014: We now have separate pages for each Spectral edit effect.

Spectral edit multi tool

Spectral edit multi tool (and Spectral edit parametric EQ and Spectral edit shelves described immediately following) are intended for working on a combined frequency and time selection made when using one of the spectrogram views.

If a fully defined spectral selection has been made, choosing Spectral edit multi-tool applies the appropriate filter for the selection. See Spectral edit multi tool for more information.

Spectral edit parametric EQ...

If a fully defined spectral selection has been made, the effect applies a band cut or band boost according to the value you enter in the "Gain (dB)" control. See Spectral edit parametric EQ for more information.

Spectral edit shelves...

If a fully defined spectral selection has been made, the effect applies a low shelf filter, high shelf filter or combined low and high shelf filter according to the value you enter in the "Gain (dB)" control. See Spectral edit shelves for more information.

Studio Fade Out

Produces a smooth and musical sounding fade out, by applying a sinusoidal fade with a progressive low pass filter from full spectrum at the start of the selection to 100 Hz at the end.

Tremolo...

Modulates the volume of the selection at the depth and rate selected in the dialog. The same as the tremolo effect familiar to guitar and keyboard players.

Vocal Remover (for center-panned vocals)...

Attempts to remove center-panned audio from a stereo track; vocals are often (but not always) recorded in this way. Vocals (or other audio) can only be removed with this plugin when panned to center, in other words sounding equally loud in both left and right channels. Help text is available from within the effect's dialog box.

Vocoder...

Vocoder synthesizes a modulator (usually a voice) in the left channel of a stereo track with a carrier wave in the right channel to produce a modified version of the left channel. Vocoding a normal voice with white noise as provided in the effect will produce a robot-like voice for special effects. Other carriers can be used for subtly different voices. Vocoder can only be applied to unsplit stereo tracks.

LADSPA Effects

Peter 30Jun13: All the LADSPA effects still carry author attribution in the latest (20Jun) alpha Audacity.
  • Gale 06Jul13: It's been decided that there is no "simple" solution to this - the plugin code can easily be hacked to remove the credits and license but then to strictly satisfy GPL we'd have to store the modified source code (as well as add attribution for one author). Probably both these effects will ultimately be replaced with ones written by "us".

LADSPA (Linux Audio Developer's Simple Plugin API) plugins were originally developed for the Linux platform, but ports of some plugins are available for Windows and OS X as well. Most LADSPA plugins are effects, but they are also used to provide some of Audacity's built-in audio generators and can be used for audio analysis. Additional LADSPA plugins can be downloaded for Windows, Mac and Linux.

LADSPA effects support real-time preview. They do not support Import and Export of effect settings.

Loading of LADSPA effects is controlled by the Register Effects dialog.

LADSPA plugins included in Audacity

Two sample LADSPA effects are included with Windows and Mac builds of Audacity:

Hard Limiter...

An extreme compressor effect. It can sometimes be used to remove stubborn clicks.

SC4...

A stereo compressor with a variable envelope follower for RMS / peak behaviour.

Adding a LADSPA plugin

To add a LADSPA plugin, put it in the Audacity "Plug-ins" folder:

  • On Windows and OS X the "Plug-ins" folder is in the directory where Audacity resides - usually C:\Program Files on Windows or the "Applications" folder on OS X.
  • On Linux, the "plug-ins" folder is in usr/share/audacity if you installed an Audacity package supplied by your distribution, or usr/local/share/audacity if you compiled Audacity from source code. Optionally a plugin folder can be created in the home directory ~/.audacity-files/plug-ins.

Go to Effects Preferences and make sure that Image of selected radio button Check for updated plugins when Audacity starts is selected, then click OK. The next time you launch Audacity, the Register Plugins dialog will appear, listing the newly-added plugins. Check the plugins to enable them.

Audacity will also load LADSPA plugins from the following system locations:
  • All operating systems: The path specified by the LADSPA_PATH environment variable
  • additionally on OS X:
    • ~/Library/Audio/Plug-Ins/LADSPA
    • /Library/Audio/Plug-Ins/LADSPA
  • additionally on Linux/Unix:
    • ~/.ladspa
    • /usr/local/lib/ladspa
    • /usr/lib/ladspa
    • $LIBDIR/ladspa

Saving LADPSA effect settings as a User Preset

Select Save As... from the Manage menu ManageEffectMenu.pngin the effect dialog to bring up the following dialog:

SavePresetDialog W7.png

Type a name for the preset then click OK to save it in the effect as a User Preset.

LADSPA Effect Options

When you choose a LADSPA effect from the Effect Menu the dialog will have an Options...  MenuDownArrow.png choice in the Manage ManageEffectMenu.png menu. Choose that menu item to bring up the dialog illustrated below.

The settings in this dialog apply to all LADSPA effects.

Ladspa effect settings.png
  • Latency Compensation: This setting (enabled by default) compensates for waveform delay caused by LADSPA effects which preload audio data to a buffer. Compensation may not work in all cases, and for it to work, any compensation or latency reporting settings in the effect itself must be enabled. If compensation fails or if this Audacity setting is unchecked, effects that buffer audio will insert silence at the start of the processed selection and remove a corresponding amount of audio from the end of the selection. Enabling or disabling compensation is effective immediately.
Warning icon Effects in the following LV2, VST and Audio Units (Mac only) types are always third-party plugins added by the user (and also by the operating system in case of Audio Units)

LV2 Effects

LV2 effects do not support real-time preview.

LV2 is a more advanced evolution of the LADSPA plugin architecture. Note that LV2 effects in Audacity cannot yet display a full graphical interface. Each time you launch Audacity it scans for and loads all detected LV2 effects.

To add a new LV2 effect, place its complete ".lv2" folder (not the files alone) at the top level of any of the following searched for locations, then restart Audacity.

  • Windows
    • Users\<user name>\AppData\Roaming\LV2 (or Documents and Settings\<user name>\Application Data\LV2 on Windows 2000/XP)
    • Program Files\Common Files\LV2 (or Program Files (x86)\Common Files\LV2 on 64-bit systems)
  • Mac:
    • ~/.lv2
    • ~/Library/Audio/Plug-Ins/LV2
    • /Library/Audio/Plug-Ins/LV2
    • /usr/local/lib/lv2
    • /usr/lib/lv2
  • Linux:
    • ~/.lv2
    • /usr/local/lib/lv2 or /usr/local/lib64/lv2
    • /usr/lib/lv2 or /usr/lib64/lv2
Search paths where Audacity looks for LV2 plug-ins may also be specified by setting the LV2_PATH environment variable. The paths listed below are legitimate.
  • Windows:
    • %APPDATA%\LV2;%COMMONPROGRAMFILES%\LV2;%COMMONPROGRAMFILES(x86)%\LV2
  • Mac OS X:
    • $HOME/.lv2:$HOME/Library/Audio/Plug-Ins/LV2:/Library/Audio/Plug-Ins/LV2:/usr/local/lib/lv2:/usr/lib/lv2
  • Linux:
    • $HOME/.lv2:/usr/local/lib/lv2:/usr/lib/lv2 (assuming $PREFIX is /usr/local as it should be by default)

VST Effects (Windows / Mac Only)

VST effects support real-time preview.

Loading of VST Effects is controlled by the Register Plugins dialog.

Adding a new VST effect in Audacity

Gale 10Aug14: ToDo "SO" files should be added to below sentence when Audacity supports VST Linux.

To add a new VST effect, put its DLL or VST file plus any configuration files or folders it requires in the Audacity "Plug-ins" or "Plugins" folder which is in the directory where Audacity resides. You can also create a folder called "VST" in the Audacity installation directory and add VST plugins there.

Alternatively, VST plugins can be placed in one of the following system locations:

  • Windows:
    • C:\Program Files\Steinberg\VSTPlugins (or C:\Program Files (x86)\Steinberg\VSTPlugins on 64-bit systems).
    • Windows Registry key HKCU\Software\VST\VSTPluginsPath
    • Windows Registry key HKLM\Software\VST\VSTPluginsPath
    • The path specified by the "VST_PATH" environment variable
  • Mac OS X:
    • ~/Library/Audio/Plug-Ins/VST
    • /Library/Audio/Plug-Ins/VST
    • The path specified by the "VST_PATH" environment variable
Gale 03Aug14: ToDo Paths are needed where VST's are searched for on Linux.
  • Steve 10Aug14: VST disabled on Linux for 2.0.6 so downgraded to Px.
  • Linux:

Then:

  1. Go to the Effects tab of Preferences
  2. Make sure that Image of selected radio button Check for updated plugins when Audacity starts is selected, then click OK.
  3. The next time you launch Audacity, the Register Plugins dialog will appear, listing the newly-added plugins. Check the plugins to enable them.
All the directories where you can place VST plugins are searched recursively, which means that plugins that are inside their own folder in that directory should still be found by Audacity.

Saving, Exporting and Importing VST Effect Presets

Not all VST effects support importing and exporting of presets. If an exported preset file is empty, the effect probably does not support presets and Audacity will not be able to import the saved presets.

Save As...

Select Save As... from the Manage menu ManageEffectMenu.png in the effect dialog to bring up the following dialog:

SavePresetDialog W7.png

Type a name for the preset then click OK to save it as a User Preset.

Export...

Presets for VST effects are exported to a file. A presets file lets you move settings for a particular effect between computers on any operating platform that supports that effect.

Select Export... from the Manage menu ManageEffectMenu.png in the effect dialog to bring up the "Save VST Preset As:" dialog

Be sure to choose a file type in the “Save as type:” dropdown menu (“Format” dropdown menu on Mac)

Type a name for the file in the "File Name" box ("Save As:" box on Mac) then click OK to export the current effect settings to a separate file.

The following file formats are supported:

  • FXP format: Default, and the most portable. It allows you to save presets for use by the same effect running in Audacity or most other VST host applications, on any computer or operating platform that supports that effect. Similarly FXP presets saved by a given effect in any VST host on any computer can be loaded into that effect in Audacity.
  • FXB format:
    ToDo-1 Bill 12Dec2014: Anyone know anything about this?
  • XML format: Less flexible, mainly useful for the small number of effects that don't support FXP presets. Most other VST host applications don't support XML, so you may only be able to share XML presets between other computers running Audacity.

By default presets are saved to the same location as the audacity.cfg file, but you can choose to save them anywhere. Since there is no distinction between preset files saved by different effects you may want to create a folder for each effect you save presets for, or include the effect name in the file name.

Warning icon

Tip when exporting VST presets

The exported VST preset file will contain the name of the preset. If you started with a named User or Factory Preset you may want to Save the settings with a unique name as a User Preset. This way, when you or someone else Imports the preset file they will not have duplicate preset names.

Warning icon Mac users take note:
Gale 10Aug14: ToDo-2 Placeholder to watch this and remove this note if the bug is fixed.
  • the FXP, FXB or XML file extension is not automatically added by Audacity - be sure to include it in the filename (for example, "myPreset.fxp")
  • make sure the file extension you add is the same as that shown in the "File Format" dropdown menu, otherwise the preset cannot be loaded.

Import...

Select Import... from the Manage menu ManageEffectMenu.png in the effect dialog to bring up the "Load VST Preset:" dialog

Navigate to the place where you exported a VST preset file.

Click the open button to load the settings.

Depending on how the particular VST effect handles importing presets, the imported preset may show up in the User Presets submenu the Factory Presets submenu or may not show up at all.

VST Effect Options

When you choose a VST effect from the Effect Menu the dialog will have an Options...  MenuDownArrow.png choice in the Manage ManageEffectMenu.png menu. Choose that menu item to bring up the dialog illustrated below.

The settings in this dialog apply to all VST effects.

VST effect settings.png
  • Buffer Size: Controls the number of samples sent to the effect in each round of processing. The default buffer size of 8192 should be safe for all VST effects. You can set a higher value which will allow faster processing but some effects may not work at higher values. Changing the buffer size is effective immediately.
  • Latency Compensation: This setting (enabled by default) compensates for waveform delay caused by VST effects which preload audio data to a buffer. Compensation may not work in all cases, and for it to work, any compensation or latency reporting settings in the effect itself must be enabled. If compensation fails or if this Audacity setting is unchecked, effects that buffer audio will insert silence at the start of the processed selection and remove a corresponding amount of audio from the end of the selection. Therefore leave this option checked unless a particular VST does not work even after reducing the buffer size, in which case you can experiment by unchecking this option. Enabling or disabling compensation is effective immediately.
  • Graphical Mode: This setting (enabled by default) allows most VST effects to display a graphical (instead of a plain text) interface. If you change this setting you must close the settings dialog, then close and reopen the effect to see the change. This option is the same as the Display VST Effects in Graphical Mode option in Effects Preferences.

Audio Unit Effects

Audio Units (AU) are a system-level plugin architecture provided on Mac OS X computers.

Audio Unit Effects support real-time preview.

Loading of Audio Unit Effects is controlled by the Register Plugins dialog.

Adding Audio Unit Effects

To add a new Audio Unit effect, place it in either of the following system plugin directories:

  • ~/Library/Audio/Plug-Ins/Components (user plugins)
  • /Library/Audio/Plug-Ins/Components (system-wide plugins)

then go to Effects Preferences and make sure that Image of selected radio button Check for updated plugins when Audacity starts is selected, then click OK. The next time you launch Audacity, the Register Plugins dialog will appear, listing the newly-added plugins. Check the plugins to enable them.

Saving, Exporting and Importing Audio Unit Effect Presets

Save As...

Select Save As... from the Manage menu ManageEffectMenu.png in the effect dialog to bring up the following dialog:

SavePresetMacDialog.png

Type a name for the preset then click OK to save it as a User Preset.

Export...

Presets for Audio Unit effects are exported to a file. A presets file lets you move settings for a particular effect between computers.

Select Export... from the Manage menu ManageEffectMenu.png in the effect dialog to bring up the following dialog:

ExportAudioUnitPresetsDialog.png

Select the user presets you want to export then click OK to export each user preset to a separate file.

Preset files are exported to /Users/<yourUserName>/Library/Audio/Presets/Apple/<effectName>/ .

Note that you must have previously Saved at least one User Preset before you can export anything.

Import...

Select Import... from the Manage menu ManageEffectMenu.png in the effect dialog to bring up the following dialog:

ImportAudioUnitPresetsDialog.png

Select the presets you want to import then click OK to import each preset file as a User Preset.

Audio Unit Effect Options

Choose Options... from the Manage menu in the Audio Unit effect dialog to bring up the Audio Unit Effect Settings dialog.

The settings in this dialog apply to all Audio Unit Effects.

AudioUnitEffectSettings.png
  • Latency Compensation: This setting (enabled by default) compensates for waveform delay caused by Audio Unit effects which preload audio data to a buffer. Compensation may not work in all cases, and for it to work, any compensation or latency reporting settings in the effect itself must be enabled. If compensation fails or if this Audacity setting is unchecked, effects that buffer audio will insert silence at the start of the processed selection and remove a corresponding amount of audio from the end of the selection. Enabling or disabling compensation is effective immediately.
  • Graphical Mode: This setting (enabled by default) allows most Audio Unit effects to display a graphical (instead of a plain text) interface. If you change this setting you must close the settings dialog, then close and reopen the effect to see the change.
Bill 12Dec2014: Apple AU effects work in Yosemite now, don't they?
Warning icon Apple Audio Units are unlikely to launch in Audacity on OS X Yosemite. Non-Apple Audio Units might do so.
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