DynamicsCompressorNode()

The DynamicsCompressorNode() constructor creates a new DynamicsCompressorNode object which provides a compression effect, which lowers the volume of the loudest parts of the signal, in order to help prevent clipping and distortion. That can occur when multiple sounds are played and multiplexed together at once.

Syntax

var dynamicsCompressorNode = new DynamicsCompressorNode(context, options)

Parameters

context
A reference to an AudioContext.
options Optional
Options are as follows:
  • attack: The amount of time (in seconds) to reduce the gain by 10dB. Its default value is 0.003. This parameter is k-rate. Its nominal range is [0, 1].
  • knee: A decibel value representing the range above the threshold where the curve smoothly transitions to the "ratio" portion. Its default value is 30. This parameter is k-rate. Its nominal range is [0, 40].
  • ratio: The amount of dB change in input for a 1 dB change in output. Its default value is 12. This parameter is k-rate. Its nominal range is [1, 20].
  • release: The amount of time (in seconds) to increase the gain by 10dB. Its default value is 0.250. This parameter is k-rate. Its nominal range is [0, 1].
  • threshold: The decibel value above which the compression will start taking effect. Its default value is -24. This parameter is k-rate. Its nominal range is [-100, 0].

Specifications

Specification Status Comment
Web Audio API
The definition of 'DynamicsCompressorNode()' in that specification.
Working Draft Initial definition.

Browser Compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support551 ?53 No42 ?
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support551551 ?5342 ?6.0

1. Before Chrome 59, the default values were not supported.

Document Tags and Contributors

Contributors to this page: fscholz, chrisdavidmills, jpmedley, david_ross
Last updated by: fscholz,