BB.AudioFX

Extends BB.AudioBase
Defined in: src/BB.AudioFX.js:13

A module for creating filter, reverb and delay effects ( abstracts the WebAudio API BiquadFilterNode, ConvolverNode and DelayNode ), for more advanced audio effects see the BB.AFX base Audio Effects module

Index

Properties

Methods

Constructor

BB.AudioFX
(
  • type
  • config
)

Defined in src/BB.AudioFX.js:13

Parameters:

  • type String

    the type of effect you want to create ( filter, reverb and delay)

  • config Object

    A config object to initialize the effect ( include examples for diff effects )

Example:


when using 'filter' type


in the example bellow the drum sampler is connected to the AudioFX ( in this case a 'filter' ), and the AudioFX is connected to the default BB.Audio destination
 BB.Audio.init();

 var filt = new BB.AudioFX('filter');

 var drum = new BB.AudioSampler({
    connect: filt,

    kick: 'audio/kick.ogg',
    snare: 'audio/snare.ogg'
 });
BB.AudioFX can also take an option config object. when using the 'filter' type, a config object can include the following:
 var filt = new BB.AudioFX('filter',{
    connect: fft,
    type: "lowpass",
    frequency: 880,
    Q: 8,
    fgain: 5,
 });
 filter types include "lowpass" (default), "highpass", "bandpass", "lowshelf", "highshelf", "peaking", "notch" and "allpass" check out the BiquadFilterNode documenation for more details on filter types and the properties ( frequency, Q, gain)
view basic BB.AudioFX 'filter' example



when using 'reverb' type


the AudioFX ( 'reverb' ), can be used just like the 'filter' example above. there's two ways to create "reverb" FX, either algorithmically ( default ) or by pasing it paths to impulse file[s] ( see conolution reverb on wikipedia)
 // algorithmically calculate convolution's impulse buffer
 var reverb = new BB.AudioFX('reverb');

 // customize algorithmically generated impulse buffer
 var reverb = new BB.AudioFX('reverb',{
    duration: 2,
    decay: 4.3,
    reverse:true
});

 // generate convolution buffer from impulse file
 var reverb = new BB.AudioFX('reverb',{
    paths: ['audio/impulse.wav']
});
 check out the ConvolutionNode documenation for more info
view basic BB.AudioFX 'reverb' example



when using 'delay' type


the AudioFX ( 'delay' ), can be used just like the 'filter' example above.
 var delay = new BB.AudioFX('delay');

 // with optional config
 var delay = new BB.AudioFX('delay',{
    max: 5, // max delay time
    time: 1 // current delay time
});

 // modify delay time afterwards
 delay.time = 3.2;
check out the DelayNode documenation for more info
view basic BB.AudioFX 'delay' example

Properties

ctx AudioContext default:BB.Audio.context

Inherited from BB.AudioBase: src/BB.AudioBase.js:39

the Audio Context this derived from

dry Number default:0

Defined in src/BB.AudioFX.js:213

the dry channel gain/volume

fgain Number

Defined in src/BB.AudioFX.js:358

fgain value when type is 'filter'

frequency Number

Defined in src/BB.AudioFX.js:343

frequency value when type is 'filter'

gain GainNode private

Inherited from BB.AudioBase: src/BB.AudioBase.js:57

the "output" gain node ( use .volume, .setGain() to interface with this )

Q Number

Defined in src/BB.AudioFX.js:373

Q value when type is 'filter'

time Number default:0

Defined in src/BB.AudioFX.js:502

the delay time (up to max specified)

volume Number default:1

Inherited from BB.AudioBase: src/BB.AudioBase.js:89

the master volume (of output gain node)

wet Number default:1

Defined in src/BB.AudioFX.js:234

the wet channel gain/volume

There are no properties that match your current filter settings. You can change your filter settings in the index section on this page. index

Methods

calcFrequencyResponse
(
  • length
)

Defined in src/BB.AudioFX.js:390

"filter" type only.
calculate the frequency response for a length-specified list of audible frequencies ( can be used to draw a curve representing the filter )

Parameters:

  • length Number

    the length of the frequency/response arrays
     var freqRes = filt.calcFrequencyResponse( canvas.width );



     // maths via: http://webaudioapi.com/samples/frequency-response/
     var dbScale = Math.round(canvas.height/4);
     var dbScale2 = Math.round(canvas.height/12.5);
     var pixelsPerDb = (0.5 * canvas.height) / dbScale;
     ctx.beginPath();
     for (var i = 0; i < canvas.width; ++i) {
        var mr = freqRes.magResponse[i];
        var dbResponse = dbScale2 * Math.log(mr) / Math.LN10;
        var x = i;
        var y = (0.5 * canvas.height) - pixelsPerDb * dbResponse;
        if ( i == 0 ) ctx.moveTo( x, y );
        else ctx.lineTo( x, y );
     }
     ctx.stroke();
    view basic BB.AudioFX 'filter' example

connect
(
  • destination
  • output
  • input
)

Inherited from BB.AudioBase: src/BB.AudioBase.js:109

connects the Noise to a particular AudioNode or AudioDestinationNode

Parameters:

  • destination AudioNode

    the AudioNode or AudioDestinationNode to connect to

  • output Number

    which output of the the Noise do you want to connect to the destination

  • input Number

    which input of the destination you want to connect the Noise to

Example:


 BB.Audio.init();

 var node = new BB.AudioBase({
    volume: 0.75,
 });

  node.connect( exampleNode );
  // connected to both default BB.Audio.context && exampleNode
  // so if exampleNode is also connected to BB.Audio.context by default,
  // ...then you've got node connected to BB.Audio.context twice
...which looks like this ( where the first Gain is the Noise and the second is the exampleNode )

disconnect
(
  • destination
  • output
  • input
)

Inherited from BB.AudioBase: src/BB.AudioBase.js:153

diconnects the Noise from the node it's connected to

Parameters:

  • destination AudioNode

    what it's connected to

  • output Number

    the particular output number

  • input Number

    the particular input number
     BB.Audio.init();

     var node = new BB.AudioBase({
        volume: 0.75,
     });

     node.disconnect(); // disconnected from default BB.Audio.context
     node.connect( exampleNode ); // connected to exampleNode only
    ...which looks like this ( where the first Gain is the node and the second is the exampleNode )

setDryGain
(
  • num
  • ramp
)

Defined in src/BB.AudioFX.js:255

set's the dry gain ( && adjust the wet gain accordingly, so that they total to 1 )

Parameters:

  • num Number

    a float value, 1 being the default volume, below 1 decreses the volume, above one pushes the gain

  • ramp Number

    value in seconds for how quickly/slowly to ramp to the new value (num) specified

Example:


 BB.Audio.init();

 var fx = new BB.AudioFX('filter');
 var noise = new BB.AudioNoise({
    connect: fx
 });

  fx.setDryGain( 0.75, 2 ); // raises dry level from 0 - 0.75 over 2 seconds (wet level drops to 0.25)
// if no ramp value is needed, you could alternatively do
  fx.dry.volume = 0.75; // immediately jumps to 0.75 (and wet to 0.25)

setGain
(
  • num
  • ramp
)

Inherited from BB.AudioBase: src/BB.AudioBase.js:197

sets the gain level of the node ( in a sense, master volume control )

Parameters:

  • num Number

    a float value, 1 being the default volume, below 1 decreses the volume, above one pushes the gain

  • ramp Number

    value in seconds for how quickly/slowly to ramp to the new value (num) specified

Example:


 BB.Audio.init();

 var node = new BB.AudioBase({
    volume: 0.75
 });

  node.setGain( 0.25, 2 ); // lower's volume from 0.75 to 0.25 in 2 seconds
// if no ramp value is needed, you could alternatively do
  node.volume = 0.5; // immediately jumps from 0.25 to 0.5

setWetGain
(
  • num
  • ramp
)

Defined in src/BB.AudioFX.js:294

set's the wet gain ( && adjust the dry gain accordingly, so that they total to 1 )

Parameters:

  • num Number

    a float value, 1 being the default volume, below 1 decreses the volume, above one pushes the gain

  • ramp Number

    value in seconds for how quickly/slowly to ramp to the new value (num) specified

Example:


 BB.Audio.init();

 var fx = new BB.AudioFX('filter');
 var noise = new BB.AudioNoise({
    connect: fx
 });

  fx.setWetGain( 0.15, 2 ); // drops wet level from 1 - 0.15 over 2 seconds (dry level rises to 0.85)
// if no ramp value is needed, you could alternatively do
  fx.wet.volume = 0.15; // immediately jumps to 0.15 (and dry to 0.85)

useImpuse
(
  • index
)

Defined in src/BB.AudioFX.js:449

"reverb" type only.
when using impulse files, you can use this method to switch between the different files initially loaded in the 'paths' when the AudioFX 'reverb' was instantiated

Parameters:

  • index Number

    of impulse.buffers to be used
     var reverb = new BB.AudioFX('reverb',{
        paths:[
            'audio/giant_hall.wav',
            'audio/small_room.wav',
            'audio/telephone.wav'
        ]
    });

     // by default 'audio/giant_hall.wav' (or reverb.impulse.buffers[0]) is used
     // below we switch to small_room.wav (or reverb.impulse.buffers[1])
     reverb.useImpulse(1);     view basic BB.AudioFX 'reverb' example

There are no methods that match your current filter settings. You can change your filter settings in the index section on this page. index