Effect Menu

Does our compressor make "soft sounds louder"? Only if you normalize? - Gale

Audacity includes many built-in effects and also lets you use a wide range of plug-in effects. You can download many free plugins for Audacity on http://audacity.sourceforge.net/download/plugins. More information is also available at http://www.kvr-vst.com, http://www.plugin.org.uk/ and http://www.ladspa.org/. 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.

ToDo Move and merge anything useful in the old Noise Removal text (greyed out in the detailed text) into Noise Removal.

Classes of Effect

There are four classes of effects - the built-in Effects, and three classes of plug-in effect which allow you to download and install additional effects. All classes of effect are applied in the same way. The four effects classes are:

Mac users also have access to Audio Unit effects. Do we want to note that here, or further down under LADSPA effects?

• Built-in Effects
• VST Effect Plug-ins
• Nyquist Effect Plug-ins
• LADSPA Effect Plug-ins

Purpose of Effects

Effects in any of the four classes can perform similar tasks. These are Audacity's built-in effects grouped by purpose:

Volume changes

(no effect on tone quality)

Amplify Auto Duck Compressor Fade In Fade Out Leveller Normalize To Do: create additional links

Tone changes

Bass Boost Echo Equalization Phaser Wahwah To Do: create additional links

Pitch and tempo changes

Change Pitch without changing tempo Change Tempo without changing pitch Change Speed affecting pitch and tempo To Do: create links

Audio restoration

Click Removal Noise Removal Repair Truncate Silence To Do: create additional links

Other built-in effects

Invert Repeat Nyquist Prompt Reverse To Do: create additional links

Most built-in effects have a "Preview" button. This allows you to listen to how the first three seconds of your selected audio will sound with your effect applied. If it does not sound quite as you want, simply adjust the controls of the effect and preview again. The preview length can be changed on the Playback tab of Preferences.

Generate and Analyze plug-ins

Nyquist plug-ins are also used to provide some of Audacity's built-in audio generators and analysis tools. You can similarly add either Nyquist or LADSPA generation and analysis plug-ins to Audacity which will then appear under the Generate or Analyze Menu.

List of Built-in Effects

Amplify...

This effect 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.

BassBoost...

This is a safe, smooth filter which can amplify the lower frequencies while leaving most of the other frequencies alone. It is most effective if you don't try to boost too much; 12 dB is usually just right.

When we get around to creating the page for this effect ... this appears to be a shelving control with a 6 dB/octave slope.

Compressor...

Compresses the dynamic range by making the soft parts louder, and the loud parts softer.?????? More details here

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 linear fade-in to the selected audio - the rapidity of the fade-in depends entirely on the length of the selection it is applied to. For a more customizable logarithmic fade, use the Envelope Tool on the Tools Toolbar.

Fade Out

Applies a linear fade-out to the selected audio - the rapidity of the fade-out depends entirely on the length of the selection it is applied to. For a more customizable logarithmic fade, use the Envelope Tool on the Tools Toolbar.

Do we want this image here? It is NOT showing the use of the envelope tool as implied by the preceding text. I don't think we need images for these simple fade effects, and I don't think they need their own pages. - Bill

Invert

This effect flips the audio samples upside-down. This normally does not affect the sound of the audio at all. It is occasionally useful, for example when the left and right channels of a song both contain equal amounts of vocals, but unequal amounts of background instruments. By inverting one of the channels and not the other and then converting from stereo to mono, the vocals will cancel each other out, leaving just the instrumentals. This only works if the exact same vocal signal is present in both of the channels to begin with.

Noise Removal...

This effect is ideal for removing 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.

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 very short click, pop, or other glitch no more than 128 samples long

Reverse

This effect reverses the selected audio temporally; after the effect the end of the audio will be heard first and the beginning last. Some people reverse small portions of audio to make inappropriate language unintelligible, while others believe you can hear subliminal messages if you listen to speech backwards. You can also create interesting sound effects by recording natural events and reversing the audio.

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.

This effect 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 WahWah effect automatically adjusts the phase of the left and right channels when given a stereo recording, so that the effect seems to travel across the speakers.

VST Effects

• To use a VST plug-in effect, put the effect in the directory (folder) called "Plug-Ins", which should be in the same directory where Audacity resides. If there is no directory, create one.
• You will also need to download and unzip the [Enabler] To do: broken link to the same directory.
• The next time you launch Audacity, any plug-ins you added will appear in the Effect menu.

Nyquist Effects

• To use a Nyquist effect, put the effect in the directory (folder) called "Plug-Ins", which should be in the same directory where Audacity resides. Upon installation, some nyquist scripts are included, so you needn't worry about creating this directory.
• The next time you launch Audacity, any plug-ins you added will appear in the Effect, Generate or Analyze menus.

LADSPA Effects

These originally started out in a Linux plugin format under the Linux Audio Developer's Simple Plugin API, but can now be used in Windows and OS X as well. There are lots of free plugins available, and no enabler is needed. More information can be found on the web.

ToDo additional plug-ins included in Windows and Mac release builds

Getting a good reverb sound depends a lot on the source audio and can take a lot of experimentation. One good strategy is to select a small portion of audio (a few seconds) and try to add reverb. Listen to it, then Undo and try it again with different settings. Keep doing this until you've found the settings you like the sound of best, and then Undo one last time, Select All, then apply the effect to your entire recording.