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

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DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidiOS SafariSamsung Internet
Basic supportChrome Full support 55
Notes
Full support 55
Notes
Notes Before Chrome 59, the default values were not supported.
Edge ? Firefox Full support 53IE No support NoOpera Full support 42Safari ? WebView Android Full support 55
Notes
Full support 55
Notes
Notes Before version 59, the default values were not supported.
Chrome Android Full support 55
Notes
Full support 55
Notes
Notes Before Chrome 59, the default values were not supported.
Edge Mobile ? Firefox Android Full support 53Opera Android Full support 42Safari iOS ? Samsung Internet Android Full support 6.0

Legend

Full support  
Full support
No support  
No support
Compatibility unknown  
Compatibility unknown
See implementation notes.
See implementation notes.

Document Tags and Contributors

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