This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for usage in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the specification changes.
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
| Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
|---|---|---|---|---|---|
| Basic support | 55[1] | ? | ? | 42 | ? |
| Feature | Android Webview | Chrome for Android | Firefox Mobile (Gecko) | Firefox OS | IE Mobile | Opera Mobile | Safari Mobile |
|---|---|---|---|---|---|---|---|
| Basic support | 55[1] | 55[1] | ? | ? | ? | 42 | ? |
[1] Before Chrome 59, the default values were not supported.