Adaptive Limiter

The Adaptive Limiter is a versatile tool for controlling the perceived loudness of sounds. It works by rounding and smoothing peaks in the signal, producing an effect similar to an analog amplifier being driven hard. Like an amplifier, it can slightly color the sound of the signal. You can use the Adaptive Limiter to achieve maximum gain, without introducing generally unwanted distortion and clipping, which can occur when the signal exceeds 0 dBFS.

The Adaptive Limiter is typically used on the final mix, where it may be placed after a compressor, such as the Multipressor, and before a final gain control, resulting in a mix of maximum loudness. The Adaptive Limiter can produce a louder-sounding mix than can be achieved by normalizing the signal.

Note: Using the Adaptive Limiter adds latency when the Lookahead parameter is active. Usually it should be used on the entire clip sequence, which may be achieved by creating a compound clip and applying the effect to that top-level clip.

Figure. Adaptive Limiter window.
  • Input meters (to the left): Show the input levels in real time as the file or project plays. The Margin field shows the highest input level. You can reset the Margin field by clicking it.
  • Input Scale knob and field: Scales the input level. Scaling is useful for handling very high-level or low-level input signals. It essentially squeezes the higher and lower signal levels into a range that allows the Gain knob to work effectively. In general, the input level should never exceed 0 dBFS, which can result in unwanted distortion.
  • Gain knob and field: Sets the amount of gain after input scaling.
  • Out Ceiling knob and field: Sets the maximum output level, or ceiling. The signal will not rise above this.
  • Output meters (to the right): Show output levels, allowing you to see the results of the limiting process. The Margin field shows the highest output level. You can reset the Margin field by clicking it.
  • Mode buttons (Extended Parameters area): Choose the type of peak smoothing:
    • OptFit: Limiting follows a linear curve, which allows signal peaks above 0 dB.
    • NoOver: Avoids distortion artifacts from the output hardware by ensuring that the signal does not exceed 0 dB.
  • Lookahead field and slider (Extended Parameters area): Adjusts how far ahead the Adaptive Limiter analyzes the file for peaks.
  • Remove DC checkbox (Extended Parameters area): Enable to activate a highpass filter that removes direct current (DC) from the signal. DC can be introduced by lower-quality audio hardware.