Amplify effect

The Amplitude And Compression > Amplify effect boosts or attenuates an audio signal. Because the effect operates in real time, you can combine it with other effects in the Effects Rack.

Gain sliders

Boost or attenuate individual audio channels.

Link Sliders

Moves the channel sliders together.

Channel Mixer effect

The Amplitude and Compression > Channel Mixer effect alters the balance of stereo or surround channels, letting you change the apparent position of sounds, correct mismatched levels, or address phasing issues.

Channel tabs

Select the output channel.

Input channel sliders

Determine the percentage of the current channels to mix into the output channel. For a stereo file, for example, an L value of 50 and an R value of 50 results in an output channel that contains equal audio from the current left and right channels.

Invert

Inverts a channel’s phase. (To understand this key audio concept, see How sound waves interact.) Inverting all channels causes no perceived difference in sound. Inverting only one channel, however, can greatly change the sound.

DeEsser effect

The Amplitude and Compression > DeEsser effect removes sibilance, “ess” sounds heard in speech and singing that can distort high frequencies.

The graph reveals the processed frequencies. Click the Preview button  to see how much audio content exists in the processed range.

Mode

Choose Broadband to uniformly compress all frequencies or Multiband to only compress the sibilance range. Multiband is best for most audio content but slightly increases processing time.

Threshold

Sets the amplitude above which compression occurs.

Center Frequency

Specifies the frequency at which sibilance is most intense. To verify, adjust this setting while playing audio.

Bandwidth

Determines the frequency range that triggers the compressor.

Tip: To visually adjust Center Frequency and Bandwidth, drag the edges of the selection in the graph.

Output Sibilance Only

Lets you hear detected sibilance. Start playback, and fine-tune settings above.

Gain Reduction

Shows the compression level of the processed frequencies.

Dynamics Processing effect

The Amplitude And Compression > Dynamics Processing effect can be used as a compressor, limiter, or expander. As a compressor and limiter, this effect reduces dynamic range, producing consistent volume levels. As an expander, it increases dynamic range by reducing the level of low‑level signals. (With extreme expander settings, you can create a noise gate that totally eliminates noise below a specific amplitude threshold.)

The Dynamics Processing effect can produce subtle changes that you notice only after repeated listening. When applying this effect in the Waveform Editor, use a copy of the original file so you can return to the original audio if necessary.

Note:

Use the Broadcast Limiter preset to simulate the processed sound of a contemporary radio station.

Dynamics tab

Graph

Depicts input level along the horizontal ruler (x‑axis) and the new output level along the vertical ruler (y‑axis). The default graph, with a straight line from the lower left to the upper right, depicts a signal that has been left untouched; every input level has the same output level. Adjusting the graph changes the relationship between input and output levels, altering dynamic range.

For example, if a desirable sonic element occurs around ‑20 dB, you can boost the input signal at that level, but leave everything else unchanged. You can also draw an inverse line (from the upper left to the lower right) that will dramatically boost quiet sounds and suppress loud ones.

Add point 

Adds control point in graph using numerical input and output levels you specify. This method is more precise than clicking the graph to add points.

Tip: To numerically adjust an existing control point, right-click it, and choose Edit Point.

Delete point 

Removes selected point from the graph.

Invert 

Flips the graph, converting compression into expansion, or vice versa.

note: You can invert a graph only if it has points in the two default corners (‑100, ‑100 and 0, 0) and if its output level increases from left to right (that is, each control point must be higher than the one to its left).

Reset 

Resets the graph to its default state.

Spline Curves

creates smoother, curved transitions between control points, rather than more abrupt, linear transitions. (See About spline curves for graphs.)

Make-Up Gain

Boosts the processed signal.

Settings tab

General

Provides overall settings.

Look-Ahead Time

Addresses transient spikes that can occur at the onset of extremely loud signals that extend beyond the compressor’s Attack Time settings. Extending Look-Ahead Time causes compression to attack before the audio gets loud, ensuring that amplitude never exceeds a certain level. Conversely, reducing Look-Ahead Time may be desirable to enhance the impact of percussive music like drum hits.

Noise Gating

Completely silences signals that are expanded below a 50-to-1 ratio.

Level Detector

Determines the original input amplitude.

Input Gain

Applies gain to the signal before it enters the Level Detector.

Attack Time

Determines how many milliseconds it takes for the input signal to register a changed amplitude level. For example, if audio suddenly drops 30 dB, the specified attack time passes before the input registers an amplitude change. This avoids erroneous amplitude readings due to temporary changes.

Release Time

Determines how many milliseconds the current amplitude level is maintained before another amplitude change can register.

Tip: Use fast attack and release settings for audio with fast transients, and slower settings for less percussive audio.

Peak mode

Determines levels based on amplitude peaks. This mode is a bit more difficult to use than RMS, because peaks aren’t precisely reflected in the Dynamics graph. However, it can be helpful when audio has loud transient peaks you want to subdue.

RMS mode

Determines levels based on the root-mean-square formula, an averaging method that more closely matches the way people perceive volume. This mode precisely reflects amplitudes in the Dynamics graph. For example, a limiter (flat horizontal line) at ‑10 dB reflects an average RMS amplitude of ‑10 dB.

Gain Processor

Amplifies or attenuates the signal depending on the amplitude detected.

Output Gain

Applies gain to the output signal after all dynamics processing.

Attack Time

Determines how many milliseconds it takes for the output signal to reach the specified level. For example, if audio suddenly drops 30 dB, the specified attack time passes before the output level changes.

Release Time

Determines how many milliseconds the current output level is maintained.

note: If the sum of Attack and Release times is too short (less than about 30 milliseconds), audible artifacts can be heard. To see good attack and release times for different types of audio content, choose various options from the Presets menu.

Link Channels

Processes all channels equally, preserving the stereo or surround balance. For example, a compressed drum beat on the left channel will reduce the right channel level by an equal amount.

Band Limiting

Restricts dynamics processing to a specific frequency range.

Low Cutoff

Is the lowest frequency that dynamics processing affects.

High Cutoff

Is the highest frequency that dynamics processing affects.

Fade Envelope effect

Choose Fade Envelope (Effects > Amplitude and Compression) to reduce amplitude by varying amounts over time.

In the Waveform Editor panel, click the yellow envelope line to add keyframes, and drag them up or down to change amplitude. To quickly select, reposition, or delete multiple keyframes, see Adjust automation with keyframes.

Note:

Select the Spline Curves option to create smoother, curved transitions between keyframes, rather than linear transitions. See About spline curves for graphs.

Gain Envelope effect

Choose Gain Envelope (Effects > Amplitude and Compression) to boost or reduce amplitude over time.

In the Waveform Editor panel, click the yellow envelope line to add keyframes, and drag them up or down to change amplitude. To quickly select, reposition, or delete multiple keyframes, see Adjust automation with keyframes.

Note:

Select the Spline Curves option to create smoother, curved transitions between keyframes, rather than linear transitions. See About spline curves for graphs.

Hard Limiter effect

The Amplitude And Compression > Hard Limiter effect greatly attenuates audio that rises above a specified threshold. Typically, limiting is applied with an input boost, a technique that increases overall volume while avoiding distortion.

Maximum Amplitude

Sets the maximum sample amplitude allowed.

Tip: To avoid clipping when working with 16‑bit audio, set this value to no more than ‑0.3 dB. If you set it even lower, to ‑3 dB, you’ll have a little more clearance for any future edits.

Input Boost

Preamplifies audio before you limit it, making a selection louder without clipping it. As you increase this level, compression increases. Try extreme settings to achieve the loud, high‑impact audio heard in contemporary pop music.

Look-Ahead Time

Sets the amount of time (in milliseconds) generally needed to attenuate the audio before the loudest peak is hit.

note: Make sure that the value is at least 5 milliseconds. If this value is too small, audible distortion effects may occur.

Release Time

Sets the time (in milliseconds) needed for the attenuation to rebound back 12 dB (or roughly the time needed for audio to resume normal volume if an extremely loud peak is encountered). In general, a setting of around 100 (the default) works well and preserves very low bass frequencies.

note: If this value is too large, audio may remain very quiet and not resume normal levels for a while.

Link Channels

Links the loudness of all channels together, preserving the stereo or surround balance.

Multiband Compressor effect

The Amplitude And Compression > Multiband Compressor effect lets you independently compress four different frequency bands. Because each band typically contains unique dynamic content, multiband compression is a particularly powerful tool for audio mastering.

Controls in the Multiband Compressor let you precisely define crossover frequencies and apply band‑specific compression settings. Click Solo buttons to preview bands in isolation, or Bypass buttons to pass bands through without processing. After you fine‑tune individual bands, select Link Band Controls to adjust them globally, and then optimize overall volume with the Output Gain slider and Limiter settings.

Note:

To change compression settings over time, use automation lanes in the Multitrack Editor. (See Automating track settings.)

Adjusting a crossover frequency in the Multiband Compressor

A. Frequency bands B. Crossover markers C. Bypassed band (no processing applied) D. Amplitude scale E. Frequency scale 

Crossover

Sets the crossover frequencies, which determine the width of each band. Either enter specific Low, Midrange, and High frequencies, or drag the crossover markers above the graph.

Band‑specific controls in the Multiband Compressor

A. Solo B. Bypass C. Threshold slider D. Input Level meters E. Gain Reduction meters 

Solo buttons

Let you hear specific frequency bands. Enable one Solo button at a time to hear bands in isolation, or enable multiple buttons to hear two or more bands together.

Bypass buttons

Bypass individual bands so they pass through without processing.

Tip: Alt‑click (Windows) or Option-click (Mac OS) Solo or Bypass buttons to quickly apply a unique setting to one band.

Threshold sliders

Set the input level at which compression begins. Possible values range from ‑60 to 0 dB. The best setting depends on audio content and musical style. To compress only extreme peaks and retain more dynamic range, try thresholds around 5 dB below the peak input level; to highly compress audio and greatly reduce dynamic range, try settings around 15 dB below the peak input level.

Input Level meters

Measure input amplitude. Double‑click the meters to reset peak and clip indicators.

Gain Reduction meters

Measure amplitude reduction with red meters that extend from top (minimal reduction) to bottom (maximum reduction).

Gain

Boosts or cuts amplitude after compression. Possible values range from ‑18 to +18 dB, where 0 is unity gain.

Ratio

Sets a compression ratio between 1‑to‑1 and 30‑to‑1. For example, a setting of 3.0 outputs 1 dB for every 3 dB increase above the compression threshold. Typical settings range from 2.0 to 5.0; higher settings produce the extremely compressed sound often heard in pop music.

Attack

Determines how quickly compression is applied when audio exceeds the threshold. Possible values range from 0 to 500 milliseconds. The default, 10 milliseconds, works well for a wide range of audio. Faster settings may work better for audio with fast transients, but such settings sound unnatural for less percussive audio.

Release

Determines how quickly compression stops after audio drops below the threshold. Possible values range from 0 to 5000 milliseconds. The default, 100 milliseconds, works well for a wide range of audio. Try faster settings for audio with fast transients, and slower settings for less percussive audio.

Output Gain

Boosts or cuts overall output level after compression. Possible values range from ‑18 to +18 dB, where 0 is unity gain. Double‑click the meters to reset peak and clip indicators.

Limiter

Applies limiting after Output Gain, at the end of the signal path, optimizing overall levels. Specify Threshold, Attack, and Release settings that are less agressive than similar band‑specific settings. Then specify a Margin setting to determine the absolute ceiling relative to 0 dBFS.

Tip: To create extremely compressed audio, enable the Limiter, and then experiment with very high Output Gain settings.

Spectrum On Input

Displays the frequency spectrum of the input signal, rather than the output signal, in the multiband graph. To quickly see the amount of compression applied to each band, toggle this option on and off.

Brickwall Limiter

Applies immediate, hard limiting at the current Margin setting. (Deselect this option to apply slower soft limiting, which sounds less compressed but may exceed the Margin setting.)

note: The maximum Attack time for brickwall limiting is 5 ms.

Link Band Controls

Lets you globally adjust the compression settings for all bands, while retaining relative differences between bands.

Tip: To temporarily link band controls, hold down Alt+Shift (Windows) or Option+Shift (Mac OS). To reset a control in all bands, hold down Ctrl+Alt+Shift (Windows) or Command+Option+Shift (Mac OS), and click the control.

Normalize effect (Waveform Editor only)

Note:

This effect requires offline processing. While it is open, you cannot edit the waveform, adjust selections, or move the current-time indicator.

The Amplitude And Compression > Normalize effect lets you set a peak level for a file or selection. When you normalize audio to 100%, you achieve the maximum amplitude that digital audio allows—0 dBFS. If you’re sending audio to a mastering engineer, however, normalize audio to between –3 and –6 dBFS, providing a cushion for further processing.

The Normalize effect amplifies the entire file or selection equally. For example, if the original audio reaches a loud peak of 80% and a quiet low of 20%, normalizing to 100% amplifies the loud peak to 100% and the quiet low to 40%.

Note:

To apply RMS normalization, choose Effects > Match Volume. If desired, you can apply that command to only one file. (See Match volume across multiple files.)

Normalize To

Sets the percentage of the highest peak relative to the maximum possible amplitude.

Tip: Select dB to enter the Normalize value in decibels instead of a percentage.

Normalize All Channels Equally

Uses all channels of a stereo or surround waveform to calculate the amplification amount. If this option is deselected, the amount is calculated separately for each channel, potentially amplifying one considerably more than others.

DC Bias Adjust

Lets you adjust the position of the waveform in the wave display. Some recording hardware may introduce a DC bias, causing the recorded waveform to appear to be above or below the normal center line in the wave display. To center the waveform, set the percentage to zero. To skew the entire selected waveform above or below the center line, specify a positive or negative percentage.

Single-band Compressor effect

The Amplitude And Compression > Single-band Compressor effect reduces dynamic range, producing consistent volume levels and increasing perceived loudness. Single-band compression is particularly effective for voice-overs, because it helps the speaker stand out over musical soundtracks and background audio.

Note:

For examples of highly-compressed audio, listen to recordings of modern pop music. By contrast, most jazz recordings are lightly compressed, while typical classical recordings feature no compression at all.

Threshold

Sets the input level at which compression begins. The best setting depends on audio content and style. To compress only extreme peaks and retain more dynamic range, try thresholds around 5 dB below the peak input level. To highly compress audio and greatly reduce dynamic range, try settings around 15 dB below the peak input level.

Ratio

Sets a compression ratio between 1‑to‑1 and 30‑to‑1. For example, a setting of 3 outputs 1 dB for every 3-dB increase above the threshold. Typical settings range from 2 to 5; higher settings produce the extremely compressed sound often heard in pop music.

Attack

Determines how quickly compression starts after audio exceeds the Threshold setting. The default, 10 milliseconds, works well for a wide range of source material. Use faster settings only for audio with quick transients, such as percussion recordings.

Release

Determines how quickly compression stops when audio drops below the Threshold setting. The default, 100 milliseconds, works well for a wide range of audio. Try faster settings for audio with fast transients, and slower settings for less percussive audio.

Output Gain

Boosts or cuts amplitude after compression. Possible values range from ‑30 dB to +30 dB, where 0 is unity gain.

Speech Volume Leveler effect

The Amplitude and Compression > Speech Volume Leveler is a compression effect that optimizes dialogue, evening out levels and removing background noise.

For the best results, do the following:

  1. Select audio with the lowest level. Set Target Volume Level and Leveling Amount to the left. Start playback, and gradually increase the Leveling Amount until speech becomes nicely audible without increasing background noise.

  2. Select audio with the highest level, and start playback. Adjust the Target Volume Level until the volume matches the loudness of the quiet passage you adjusted previously.

  3. If necessary, readjust the Leveling Amount to avoid an over-compressed sound.

Here are additional details about each option:

Target Volume Level

Sets the desired output level relative to zero dBFS. (See Measuring amplitude in dBFS.)

Leveling Amount

At low settings, amplifies speech slightly without boosting the noise floor. At high settings, amplifies the entire signal more as the signal drops closer to the noise floor.

Boost Low Signals

Interprets shorter, low-volume passages as speech that should be amplified. For most audio content, deselect this option to produce smoother sound.

Target Dynamic Range

Minimizes background noises while amplifying and leveling only speech.

For best results with most content, specify a Target Dynamic Range value between –45dB and –60dB.

Note:

Specifying a higher parameter value (up to –80dB) can significantly reduce background noise, but applies less leveling and amplification of speech content.

Specifying a lower parameter value (down to –30dB) provides better speech leveling, but may amplify the background noise more than desired.

Advanced settings

Click the triangle to access the following options:

Compressor

Maintains a strong level if the processed signal falls below a threshold relative to zero dBFS.

Noise Gate

Eliminates background noise by dramatically reducing output level when the signal drops by an offset you specify.

Tube-modeled Compressor effect

The Amplitude And Compression > Tube-modeled Compressor effect simulates the warmth of vintage hardware compressors. Use this effect to add subtle distortion that pleasantly colors audio.

Threshold slider

Sets the input level at which compression begins. Possible values range from ‑60 to 0 dB. The best setting depends on audio content and musical style. To compress only extreme peaks and retain more dynamic range, try thresholds around 5 dB below the peak input level; to highly compress audio and greatly reduce dynamic range, try settings around 15 dB below the peak input level.

Input Level meters

To the left of the slider, these meters measure input amplitude. Double‑click the meters to reset peak and clip indicators.

Gain Reduction meters

To the right of the slider, these meters measure amplitude reduction with red bars that extend from top (minimal reduction) to bottom (maximum reduction).

Gain

Boosts or cuts amplitude after compression. Possible values range from ‑18 to +18 dB, where 0 is unity gain.

Ratio

Sets a compression ratio between 1‑to‑1 and 30‑to‑1. For example, a setting of 3.0 outputs 1 dB for every 3 dB increase above the compression threshold. Typical settings range from 2.0 to 5.0; higher settings produce the extremely compressed sound often heard in pop music.

Attack

Determines how quickly compression is applied when audio exceeds the threshold. Possible values range from 0 to 500 milliseconds. The default, 10 milliseconds, works well for a wide range of audio. Faster settings may work better for audio with fast transients, but such settings sound unnatural for less percussive audio.

Release

Determines how quickly compression stops after audio drops below the threshold. Possible values range from 0 to 5000 milliseconds. The default, 100 milliseconds, works well for a wide range of audio. Try faster settings for audio with fast transients, and slower settings for less percussive audio.

Volume Envelope effect  

The Amplitude And Compression > Volume Envelope effect lets you change volume over time with boosts and fades. In the Waveform Editor panel, simply drag the yellow line. The top of the panel represents 100% (normal) amplification; the bottom represents 100% attenuation (silence).

Note:

Though the Volume Envelope effect isn’t available in the Multitrack Editor, you can use automation lanes to accomplish the same task. (See Automating track settings.)

Dragging an anchor point in the Editor panel

Yellow envelope line in Editor panel

Drag to adjust amplitude percentage, and click to add keyframes for additional boosts and fades. To quickly select, reposition, or delete multiple keyframes, see Adjust automation with keyframes.

Spline curves

Applies smoother, curved transitions between keyframes, rather than linear transitions. See About spline curves for graphs.

This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 Unported License  Twitter™ and Facebook posts are not covered under the terms of Creative Commons.

Legal Notices   |   Online Privacy Policy