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

DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
DynamicsCompressorNode() constructorChrome Full support 55
Notes
Full support 55
Notes
Notes Before Chrome 59, the default values were not supported.
Edge Full support ≤79Firefox 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.
Firefox Android Full support 53Opera Android Full support 42Safari iOS ? Samsung Internet Android Full support 6.0
Notes
Full support 6.0
Notes
Notes Before Samsung Internet 7.0, the default values were not supported.

Legend

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