Ozone’s acclaimed IRC (Intelligent Release Control) technology lets you boost the overall level of your mixes without sacrificing dynamics and clarity. The Maximizer applies to the entire bandwidth of the mix; it is not a multiband effect.


Maximizer interface

IRC Modes

The Maximizer includes the following Intelligent Release Control (IRC) modes:


Provides the intelligent loudness maximization of IRC I with lower latency.


Provides intelligent digital loudness maximization of the signal. It does this by analyzing the source material and applying limiting in a psychoacoustically pleasing manner, reacting quickly to transients (to prevent pumping) and reacting more slowly to steady bass tones (to prevent distortion).


Similar to IRC I, but optimized to preserve transients even more, so they sound sharper and clearer in the output signal, even when aggressive limiting is taking place.


Allows for the most aggressive limiting by using an advanced psychoacoustic model to intelligently determine the speed of limiting that can be done to the incoming signal, before producing distortion that is detectable to the human ear.

The IRC III mode is very CPU-intensive, and produces a high latency, especially at higher sampling rates. You may find that at sampling rates greater than 48 kHz you are unable to use IRC III mode in real-time.

The IRC modes provide intelligent release control (the release time is automatically varied depending on the audio material). However, when the Maximizer is set to IRC III mode you may also choose between four different character “styles,” which will help you manage the limiter’s sound by constraining its release behavior.

IRC III Styles

  • CLIPPING: This is the most aggressive style setting of IRC III and may be used if you wish to slightly colorize your mix with distortion or achieve the highest degree of loudness with the greatest risk of clipping.
  • CRISP: This setting aggressively constrains the limiter’s release behavior and will favor distortion over any pumping.
  • BALANCED: This setting constrains the release behavior of the limiter in a generally transparent way and should be suitable for most material.
  • PUMPING: This is the least aggressive style setting for IRC III and does not constrain the limiter’s release behavior. It can tend toward a slower release behavior and may result in pumping. This is the “legacy” setting and is the behavior used in Ozone version 5.01 and earlier.


This mode builds upon our existing IRC technology by shaping the spectrum to further reduce pumping and distortion. As the signal goes farther over the threshold, the IRC IV algorithm limits frequency bands that contribute most to these peaks. This reduces intermodulation between different signal components.

For example, given vocals and drums, this algorithm can be more selective about limiting the transients from the drums, without causing the vocals to duck as much. When no limiting is necessary, the spectrum will be unaltered.

While a typical multiband limiter has only a few bands set using crossovers, Ozone’s IRC IV algorithm uses dozens of psychoacoustically spaced bands in order to react to any type of audio.

IRC IV Styles

  • CLASSIC: This setting provides general enhancement of the overall mix with a sound more reminiscent of Ozone’s earlier limiting algorithms which are still being used by professionals today.
  • MODERN: This style also provides general enhancement and life to your mix but with greater detail and clarity than the Classic style.
  • TRANSIENT: This style is optimized for maximum preservation of all transients resulting in a highly detailed overall sound that may benefit some mixes needing added clarity.


Determines the level at which limiting will be triggered and determines the amount of gain added to maximize the output level. Setting the Threshold to a non-zero value that doesn’t trigger the limiter will still increase the output of the Maximizer. For example, if the input level to the Maximizer is peaking at -15 dB and the Maximizer Threshold is set to -4dB, limiting will not occur, but the level at the output of the Maximizer will be peaking at -11dB.

Learn Threshold

When enabled, the Maximizer will automatically adjust the Threshold slider to in response to the input audio in order to meet the Threshold Target value defined below. Double-clicking the Target LUFS value readout allows you to edit the LUFS target.

This parameter will not disable itself after learning. It can be used to continuously update the Threshold to meet the Target value.

Learn Threshold is not recommended for loudness compliance purposes

  • The Learn Threshold control is not intended to be used to meet loudness compliance standards.


Determines the maximimum output level of the Maximizer. It is generally recommended to use a setting of -0.3 dB when dithering, or a more dramatic setting (-0.6 to -0.8) when mastering audio to be converted to .mp3 or .aac later, in order to prevent clipping in the future.

When enabled, Threshold and Ceiling controls will be linked. Adjusting either control in linked mode will adjust the other control by the same amount.

True Peak

When enabled, the limiter will account for the levels of each digital sample and the levels of the analog signal that will eventually be produced by D/A conversion. Enables the limiter to take into account not only the levels of each digital sample but also the levels of the analog signal that will eventually be produced by D/A conversion. This is sometimes necessary, since an analog signal’s peak level can exceed the corresponding digital signal’s peak level by more than 3 dB.

True Peak Limiting & CPU Usage

This option will result in a small increase in CPU usage, but if your mixes are running very hot you may want to enable it to ensure that absolutely no distortion is introduced when your audio is finally run through a D/A converter.


Adjust the character slider to customize the overall response time of the maximizer processing.

Stereo Independence

The Stereo Independence controls represent the next iteration of the Stereo Unlink control in previous versions of Ozone. By default, the Stereo Independence controls (Transient and Sustain) will be linked and set to 0% - mimicking the default settings of the previous Stereo Unlink control.

When limiting channels independently (with both sliders set to 100%), it is possible to achieve a louder output from the Maximizer, but this can result in a narrow stereo image. To alleviate the narrowing effect of the Stereo Unlink control, we split this feature into two sliders.

When set to non-zero values, these controls apply limiting to transient and sustained material separately, based on a level envelope generated from a ratio of the individual channel levels and the entire stereo image.

  • Transient: Adjusts how the limiter responds to transient material across channels.
  • Sustain: Adjusts how the limiter responds to sustained material across channels.
  • Link: Links the Transient and Sustain sliders.

Transient Emphasis

Enable Transient Emphasis adjustment by clicking the Transient Emphasis power button. Adjusting the Amount control allows you to fine-tune the shaping of transients before limiting takes place. This can be useful for preserving sharper sounds, like drums, while still optimizing loudness.


  • Using higher Amount values for Transient Emphasis will result in more pronounced transients after the limiting process.


Threshold Meter

Maximizer threshold meter

The Threshold meter displays the input level to the Maximizer alongside the gain reduction applied by the Maximizer. The two meters on the far left and right of the threshold meter display the input audio level and the two meters that appear in between the input meters display the gain reduction being applied by the Maximizer.

Mini-metering Views

The Maximizer includes mini-metering views above the controls area.

Gain Reduction Trace

gain reduction

A scrolling meter that displays the incoming signal’s waveform with a superimposed trace that illustrates the amount of gain reduction taking place over time. The Gain Reduction Trace can help you to set attack and release controls appropriately and monitor the envelope of gain reduction.

Spectrum Analyzer


Displays the real-time spectrum of the output of Ozone.