Back to overview Documentation version 9.23


Low Level Boost section

Increases the level of very soft sounds.

This can be useful for classical music. Very soft bits can be pulled up in level without compressing the rest. So the audio stays dynamic, but the soft parts are still louder. It's probably not useful for other types of content.

General panel

Main Low Level Boost settings.

  • Low Level Boost
    Enables Low Level Boost.

Levels panel

Sets the levels at which Low Level Boost works.

  • Boost audio below
    Audio level is boosted if it falls below this level.

  • Max boost
    Maximum amount of boost of the low levels.

  • Sudden jump protection threshold
    If the level increases by more than this, the level boost is very quickly reduced.

Compatibility panel

Compatibility settings for older presets.

  • Legacy mode
    Needed for older presets.

    Do not turn this on.

Attack panel

Attack settings.

  • Attack
    The time a 86% volume reduction due to a higher input level takes.

    If the input level increases a bit, the volume goes down more slowly than if it increases a lot. This means that it's not possible to give a value in dB/ms.

  • Max Attack Speed
    The maximum attack speed.

    This is for the "automatic/hydraulic door" behavior: Push harder against it and at some point (this speed) it won't move faster anymore.

Release panel

Release settings.

  • Release (time to raise 10 dB)
    The time it takes for the output level to climb by 10 dB if the input level falls silent.

  • Max Release Speed
    The maximum release speed.

    Similar to Max Attack Speed, but for release.

  • Exponential Release
    Release faster if the input level drops more.

Release Gate panel

The release gate settings.

  • Gate speed
    Determines how fast the gate closes.

    This value is relative to Release Time.

  • Gate freeze
    Level below which all release action stops.

    If the output audio is below this level, release stops completely. Be careful with this, if it is set too high, it can cause the compressor to not come back after a big spike!

    See also Gate slowdown.

  • Gate slowdown
    If the input level is lower than this, release is slowed down.

Detection panel

Controls level detection.

  • ITU-BS.1770 Bass
    Measures bass levels bas on ITU-BS1770.

    This means that it responds less strongly to deep bass.

  • ITU-BS.1770 Head
    Measures highs levels based on ITU-BS1770.

    This means that it responds stronger to highs above about 1 kHz.

  • Lookahead
    Lookahead time.

    This determines how much the compressor looks ahead. For fast attack speeds (under 10 ms), this helps a lot to remove the short spikes that remain after compressing. However, we have also noticed that in some cases it can cause the sound to become more restless, so don't overuse this.

Behavior panel

Controls the compressor behavior.

  • Relative release distance
    If the level drops dramatically, this controls how fast the release can get.

    In Analog Compressor Symmetric modes, the attack and release behavior are symmetrical. This is generally a good thing: Handling attack and release the same (albeit with different speeds) is the most "natural" design. But there is one problem with this. A very big attack should be handled quickly, but if attack and release are handled the same and the level briefly drops to zero, that would also cause release to act very fast. Which may cause over-reactions.

    This setting controls what - in case of silence - the release will use as its input level.

  • Ratio
    Determines how strongly the compressor responds to changing input levels.

    Say, at one moment a sound comes in at the threshold level, so nothing happens to it. If another sound comes in at 6 dB above the theshold level, the input should be reduced by half. The ratio indicates how much of the increase in input level is not removed. At a the lowest ratio (1:1), the compressor is basically disabled. At the maximum ratio, 1000:1, 1/1000th of the increase is kept.

  • Window
    Sets an area in which the compressor stops moving.

    When a window size is set, the compressor internally behaves normally, but as long as the level stays inside the window, it doesn't move. As an example, say that a window of 1 dB is set. If the input level first goes up a lot, the compressor will go down, but the actual action runs 0.5 dB (half of the window) behind. If the input level then drops a bit, the compressor would normally rise again, but as long as it stays within the window, the output level doesn't change. Only if the compressor would rise more than 1 dB, the windowed version would start to follow again.

  • Channel linking
    Sets the maximum difference in change between the audio channels.

    For example if the left channel would be attenuated by 10 dB and the right channel by 5 dB, but channel linking is set to 2 dB, then the right channel will be attenuated by 8 dB instead. So the loudest channel pulls the other channels down to at most this many dB above its own level.

  • Lowpass below
    Lowpasses the compressor control signal.

    By lowpassing the control signal from the compressor, distortion from fast compressor action is removed. It also helps smoothe out remaining spikes when the Attack is a bit too slow, since the filtering works symetrically (not only forward in time).


Side chain section

Lets the compressor respond more or less to certain frequencies.

For example, you can boost the bass in the side chain to increase pumping caused by bass - or you can reduce it to reduce bass pumping.

  • PEQ
    Drawable equalizer.

  • Parametric settings panel

    Parametric equalizer settings.

    Instead of drawing the equalizer curve, this allows setting up the equalizer using frequencies and Q factors.

    • Use parametric settings
      Enables using parametric equalizer settings instead of drawing the equalizer curve.

    Side chain panel

    Side chain settings.

    • PEQ Sidechain
      Enables the side chain.