EZ Web Audio / Track
Class: Track
Defined in: packages/core/src/track.ts:38
Music track with position tracking, pause/resume, and seeking.
Track extends Sound with playback position awareness. Use Track for longer audio files where users need to pause, resume, or seek to specific positions. Each Track can only play once at a time (unlike Sound which allows overlap).
Example
import { createTrack } from 'ez-web-audio'
const track = await createTrack('song.mp3')
track.play()
// Pause and resume
track.pause()
track.resume()
// Seek to 30 seconds
track.seek(30).as('seconds')
// Get current position
console.log(track.position)
// { raw: 30.5, string: '0:30', pojo: { minutes: 0, seconds: 30 } }
// Check playback state
console.log(track.isPlaying) // true
console.log(track.percentPlayed) // 15.5Extends
Constructors
Constructor
new Track(
audioContext,audioBuffer,opts?):Track
Defined in: packages/core/src/sound.ts:87
Create a Sound instance.
Note: Use createSound factory function instead of calling this directly.
Parameters
audioContext
AudioContext
The AudioContext to use for audio operations
audioBuffer
AudioBuffer
The decoded audio data to play
opts?
BaseSoundOptions
Optional configuration (name, setTimeout override)
Returns
Track
Inherited from
Properties
_analyzer
protected_analyzer:Analyzer|null=null
Defined in: packages/core/src/base-sound.ts:161
Inherited from
_destination
protected_destination:AudioNode
Defined in: packages/core/src/base-sound.ts:154
Inherited from
_isPlaying
protected_isPlaying:boolean=false
Defined in: packages/core/src/base-sound.ts:84
Inherited from
_targetGain
protected_targetGain:number=1
Defined in: packages/core/src/base-sound.ts:107
The user's intended gain level (0–1). Tracks the last value set via changeGainTo() / volume setter so that gain can be restored after a fadeOut() or Oscillator anti-click stop that ramps gainNode.gain to 0.
Inherited from
audioBuffer
readonlyaudioBuffer:AudioBuffer
Defined in: packages/core/src/sound.ts:87
The decoded audio data to play
Inherited from
audioContext
readonlyaudioContext:AudioContext
Defined in: packages/core/src/base-sound.ts:218
Inherited from
audioSourceNode
audioSourceNode:
AudioBufferSourceNode
Defined in: packages/core/src/sound.ts:36
The underlying AudioBufferSourceNode that plays the audio.
Inherited from
clearTimeout()
protectedclearTimeout: (id) =>void
Defined in: packages/core/src/base-sound.ts:97
Parameters
id
number
Returns
void
Inherited from
controller
protectedcontroller:SoundController
Defined in: packages/core/src/sound.ts:39
Controller for managing gain, pan, and other audio parameters.
Inherited from
debug?
optionaldebug:boolean
Defined in: packages/core/src/base-sound.ts:216
Default
undefined (follows global debug mode)Example
sound.debug = true // enable debug for this sound
sound.debug = false // silence this sound even when global debug is onInherited from
effectChainInput
protectedeffectChainInput:GainNode
Defined in: packages/core/src/base-sound.ts:147
Inherited from
effects
protectedeffects:Effect[] =[]
Defined in: packages/core/src/base-sound.ts:140
Inherited from
gainNode
protectedgainNode:GainNode
Defined in: packages/core/src/base-sound.ts:93
The GainNode controlling this sound's volume.
For simple volume control, use changeGainTo() or update('gain'). For advanced routing, use getGainNode().
Inherited from
name
name:
string
Defined in: packages/core/src/base-sound.ts:202
Inherited from
pannerNode
protectedpannerNode:StereoPannerNode
Defined in: packages/core/src/base-sound.ts:95
Inherited from
setTimeout()
protectedsetTimeout: (fn,delayMillis) =>number
Defined in: packages/core/src/base-sound.ts:96
Parameters
fn
() => void
delayMillis
number
Returns
number
Inherited from
startedPlayingAt
protectedstartedPlayingAt:number=0
Defined in: packages/core/src/base-sound.ts:99
Inherited from
startOffset
protectedstartOffset:number=0
Defined in: packages/core/src/base-sound.ts:170
Offset in seconds from the beginning of the audio buffer where playback starts. Used internally by Track for seek/resume functionality.
Default
0See
https://developer.mozilla.org/en-US/docs/Web/API/AudioScheduledSourceNode/start
Inherited from
Accessors
_isLooping
Get Signature
get
protected_isLooping():boolean
Defined in: packages/core/src/sound.ts:74
Returns whether this sound is set to loop. Used by BaseSound.playAt() to skip the duration timeout when looping is enabled.
Returns
boolean
Inherited from
disposed
Get Signature
get disposed():
boolean
Defined in: packages/core/src/base-sound.ts:1174
Whether this instance has been disposed.
Once disposed, the instance cannot be used for playback. Create a new instance if you need to play the sound again.
Example
sound.dispose()
console.log(sound.disposed) // trueReturns
boolean
Inherited from
duration
Get Signature
get duration():
TimeObject
Defined in: packages/core/src/sound.ts:208
Get the duration of the audio buffer.
Returns a TimeObject with the duration in multiple formats:
raw: Duration in secondsstring: Formatted as 'MM:SS'pojo: Object withminutesandsecondsproperties
Example
const sound = await createSound('song.mp3')
console.log(sound.duration.raw) // 180.5
console.log(sound.duration.string) // '3:00'
console.log(sound.duration.pojo) // { minutes: 3, seconds: 0 }Returns
Inherited from
durationRaw
Get Signature
get durationRaw():
number
Defined in: packages/core/src/sound.ts:187
Get the duration of the audio buffer in seconds.
Use this instead of duration.raw in performance-sensitive code paths to avoid allocating a TimeObject.
Returns
number
Inherited from
isPlaying
Get Signature
get isPlaying():
boolean
Defined in: packages/core/src/base-sound.ts:1115
Whether the sound is currently playing.
Example
if (sound.isPlaying) {
await sound.stop()
}Returns
boolean
Inherited from
loop
Get Signature
get loop():
boolean
Defined in: packages/core/src/sound.ts:61
Enable or disable native looping for this sound.
When loop is true, the audio replays from the beginning when it reaches the end, providing gapless looping via the native AudioBufferSourceNode.loop property. Call stop() to end looped playback.
Example
const sfx = await createSound('rain.mp3')
sfx.loop = true
sfx.play() // plays continuously until stop()
// Stop looped playback
await sfx.stop()Returns
boolean
Set Signature
set loop(
value):void
Defined in: packages/core/src/sound.ts:65
Parameters
value
boolean
Returns
void
Inherited from
percentGain
Get Signature
get percentGain():
number
Defined in: packages/core/src/base-sound.ts:1127
Current gain as a percentage (0-100).
Example
console.log(`Volume: ${sound.percentGain}%`) // "Volume: 50%"Returns
number
Inherited from
percentPlayed
Get Signature
get percentPlayed():
number
Defined in: packages/core/src/track.ts:95
Get the current playback position as a percentage (0-100).
Example
const track = await createTrack('song.mp3')
track.play()
// Use for progress bar
progressBar.style.width = `${track.percentPlayed}%`Returns
number
position
Get Signature
get position():
TimeObject
Defined in: packages/core/src/track.ts:72
Get the current playback position.
Returns a TimeObject with the position in multiple formats:
raw: Position in secondsstring: Formatted as 'MM:SS'pojo: Object withminutesandsecondsproperties
Example
const track = await createTrack('song.mp3')
track.play()
// After playing for a while
console.log(track.position.raw) // 65.5
console.log(track.position.string) // '1:05'
console.log(track.position.pojo) // { minutes: 1, seconds: 5 }Returns
volume
Get Signature
get volume():
number
Defined in: packages/core/src/base-sound.ts:1150
Alias for gain. Get/set the volume (0 = silent, 1 = full volume).
Values above 1 amplify the signal and may cause distortion. The setter delegates to changeGainTo(), which throws if the value is negative and warns if it exceeds 1.
Inherited by Sound, Track, and Oscillator.
Example
sound.volume = 0.5 // set to half volume
console.log(sound.volume) // 0.5
// Works on all BaseSound subclasses
const osc = await createOscillator()
osc.volume = 0.8Returns
number
Set Signature
set volume(
value):void
Defined in: packages/core/src/base-sound.ts:1154
Parameters
value
number
Returns
void
Inherited from
Methods
_clearListeners()
protected_clearListeners():void
Defined in: packages/core/src/events/typed-event-emitter.ts:192
Remove every listener registered through this emitter (via addEventListener(), on(), or once()), regardless of how many or what event type they're bound to.
Native EventTarget has no removeAllListeners(). This works around that by aborting a shared AbortSignal threaded through every addEventListener() call this class makes, then swapping in a fresh AbortController so the instance can keep accepting new listeners afterward (e.g. if it's reused before being garbage collected).
Subclasses call this from their dispose() alongside neutering dispatchEvent — the neuter stops future emits, this stops stale listener closures from being retained/invoked at all.
Returns
void
Inherited from
_onPlaybackStarted()
protected_onPlaybackStarted():void
Defined in: packages/core/src/track.ts:108
Hook called after playback starts. Sets up the onended handler for natural completion detection and starts position tracking. Fixes H-2: emits 'end' event on natural completion instead of swallowing it.
Returns
void
Overrides
addEffect()
addEffect(
effect,position?):this
Defined in: packages/core/src/base-sound.ts:401
Add an effect to the effect chain. Effects persist across multiple play() calls.
Parameters
effect
The Effect instance to add
position?
number
Optional index to insert at (defaults to end of chain)
Returns
this
this for chaining
Example
const filter = createFilterEffect('lowpass', { frequency: 1000 })
sound.addEffect(filter)Inherited from
addEffects()
addEffects(
effects,position?):this
Defined in: packages/core/src/base-sound.ts:471
Add multiple effects to the effect chain in one call. The chain is rewired only once after all effects are added, which is more efficient than calling addEffect() multiple times.
Parameters
effects
Effect[]
Array of Effect instances to add
position?
number
Optional index to insert at (defaults to end of chain)
Returns
this
this for chaining
Example
const filter = createFilterEffect('lowpass', { frequency: 800 })
const boost = createGainEffect(1.5)
sound.addEffects([filter, boost])Inherited from
addEventListener()
Call Signature
addEventListener<
K>(type,listener,options?):void
Defined in: packages/core/src/events/typed-event-emitter.ts:44
Add a typed event listener for known event types. Overloaded to provide type safety for known event types while remaining compatible with the native EventTarget API.
Type Parameters
K
K extends "pause" | "play" | "dispose" | "stop" | "resume" | "end" | "seek"
Parameters
type
K
The event type (key of TMap)
listener
(event) => void
Typed event handler
options?
Standard addEventListener options
boolean | AddEventListenerOptions
Returns
void
Inherited from
Call Signature
addEventListener(
type,listener,options?):void
Defined in: packages/core/src/events/typed-event-emitter.ts:49
Add a typed event listener for known event types. Overloaded to provide type safety for known event types while remaining compatible with the native EventTarget API.
Parameters
type
string
The event type (key of TMap)
listener
Typed event handler
EventListenerOrEventListenerObject | null
options?
Standard addEventListener options
boolean | AddEventListenerOptions
Returns
void
Inherited from
changeGainTo()
changeGainTo(
value):this
Defined in: packages/core/src/base-sound.ts:693
Set the gain (volume) immediately.
Convenience method for update('gain').to(value).as('ratio').
Parameters
value
number
Gain from 0 (silent) to 1 (full volume)
Returns
this
this for chaining
Example
sound.changeGainTo(0.5) // Half volume
sound.changeGainTo(0) // Muted
sound.changeGainTo(1) // Full volumeInherited from
changePanTo()
changePanTo(
value):this
Defined in: packages/core/src/base-sound.ts:670
Set the pan position immediately.
Convenience method for update('pan').to(value).as('ratio').
Parameters
value
number
Pan position from -1 (left) to 1 (right), 0 is center
Returns
this
this for chaining
Example
sound.changePanTo(-1) // Hard left
sound.changePanTo(0) // Center
sound.changePanTo(1) // Hard rightInherited from
dispose()
dispose():
void
Defined in: packages/core/src/base-sound.ts:1270
Dispose this sound instance, releasing all audio resources.
Disconnects all audio nodes, clears the effect chain, cancels pending timeouts, and marks the instance as unusable. After disposing, calling play() will throw an error.
Dispose is idempotent — calling it multiple times is safe.
After disposal, event listeners registered via on() / addEventListener() will no longer fire. To free listener references for garbage collection, call off() for each listener before calling dispose().
Returns
void
Example
const sound = await createSound('click.mp3')
await sound.play()
// When done with the sound
sound.dispose()
console.log(sound.disposed) // true
// Attempting to play after dispose will throw
// sound.play() // throws Error: Cannot play a disposed soundInherited from
emit()
protectedemit<K>(type,detail):void
Defined in: packages/core/src/events/typed-event-emitter.ts:95
Emit a typed event with the given detail.
Creates a CustomEvent with the provided detail and dispatches it on this target. Subclasses call this internally to fire lifecycle events.
Type Parameters
K
K extends "pause" | "play" | "dispose" | "stop" | "resume" | "end" | "seek"
Parameters
type
K
The event type to emit (key of TMap)
detail
TrackEventMap[K]["detail"]
The event detail object (typed by TMap)
Returns
void
Inherited from
fadeIn()
fadeIn(
duration):Promise<void>
Defined in: packages/core/src/base-sound.ts:1202
Fade in the sound from silence to its current gain over duration seconds, then play.
Schedules a gain ramp from 0 to the current gain value and calls play(). The current gain is restored after playback — use changeGainTo() to set a target volume before calling fadeIn().
Parameters
duration
number
Fade-in duration in seconds
Returns
Promise<void>
Promise that resolves when playback begins
Example
const sound = await createSound('music.mp3')
await sound.fadeIn(2) // fade in over 2 secondsInherited from
fadeOut()
fadeOut(
duration):Promise<void>
Defined in: packages/core/src/base-sound.ts:1225
Fade out the sound from its current gain to silence over duration seconds, then stop.
If the sound is not playing, this is a no-op. Returns a Promise that resolves after the fade completes and stop() has been called.
Parameters
duration
number
Fade-out duration in seconds
Returns
Promise<void>
Promise that resolves when the fade and stop are complete
Example
const sound = await createSound('music.mp3')
await sound.play()
await sound.fadeOut(2) // fade out over 2 seconds then stopInherited from
getAnalyzer()
getAnalyzer():
Analyzer|null
Defined in: packages/core/src/base-sound.ts:578
Get the currently attached analyzer, if any.
Returns
Analyzer | null
The attached Analyzer instance, or null if none attached
Inherited from
getEffects()
getEffects(): readonly
Effect[]
Defined in: packages/core/src/base-sound.ts:514
Get a readonly copy of the current effects array.
Returns
readonly Effect[]
Shallow copy of the effects array
Inherited from
getGainNode()
getGainNode():
GainNode
Defined in: packages/core/src/base-sound.ts:597
Get the GainNode for this sound.
Provides controlled access to the underlying GainNode for advanced audio routing scenarios (e.g., crossfading between tracks). For simple volume control, use changeGainTo() or update('gain').
Returns
GainNode
The GainNode controlling this sound's volume
Example
const node = sound.getGainNode()
node.gain.linearRampToValueAtTime(0, ctx.currentTime + 2)Inherited from
getPannerNode()
getPannerNode():
StereoPannerNode
Defined in: packages/core/src/base-sound.ts:610
Get the StereoPannerNode for this sound.
Provides controlled access to the underlying StereoPannerNode for advanced audio routing scenarios (e.g., LFO modulation of pan position). For simple pan control, use changePanTo() or update('pan').
Returns
StereoPannerNode
The StereoPannerNode controlling this sound's pan position
Inherited from
later()
protectedlater(fn):void
Defined in: packages/core/src/base-sound.ts:1158
Parameters
fn
() => void
Returns
void
Inherited from
off()
off<
K>(type,listener):this
Defined in: packages/core/src/events/typed-event-emitter.ts:167
Unsubscribe from an event.
Note: Due to native EventTarget limitations, you must provide the same listener function reference that was used when subscribing.
Type Parameters
K
K extends "pause" | "play" | "dispose" | "stop" | "resume" | "end" | "seek"
Parameters
type
K
The event type to unsubscribe from
listener
(event) => void
The event handler function to remove
Returns
this
this for chaining
Example
const handler = (e) => console.log(e.detail)
emitter.on('play', handler)
// later...
emitter.off('play', handler)Inherited from
on()
on<
K>(type,listener):this
Defined in: packages/core/src/events/typed-event-emitter.ts:116
Subscribe to one or more events. Supports chaining.
Type Parameters
K
K extends "pause" | "play" | "dispose" | "stop" | "resume" | "end" | "seek"
Parameters
type
The event type(s) to subscribe to (key or array of keys of TMap)
K | K[]
listener
(event) => void
The event handler function
Returns
this
this for chaining
Example
emitter.on('play', handlePlay).on('stop', handleStop)
emitter.on(['play', 'stop'], handleBoth)Inherited from
once()
once<
K>(type,listener):this
Defined in: packages/core/src/events/typed-event-emitter.ts:141
Subscribe to an event once. Handler is removed after first invocation.
Type Parameters
K
K extends "pause" | "play" | "dispose" | "stop" | "resume" | "end" | "seek"
Parameters
type
K
The event type to subscribe to
listener
(event) => void
The event handler function
Returns
this
this for chaining
Example
emitter.once('end', () => console.log('Finished'))Inherited from
onPlayRamp()
onPlayRamp(
type,rampType?):object
Defined in: packages/core/src/base-sound.ts:794
Schedule a parameter ramp when play() is called.
Use this for smooth transitions like vibrato, tremolo, or automation.
Parameters
type
The parameter to ramp ('gain' or 'pan')
rampType?
RampType
Type of ramp curve ('linear' or 'exponential')
Returns
object
Fluent builder for setting start value, end value, and duration
from()
from: (
startValue) =>object
Parameters
startValue
number
Returns
object
to()
to: (
endValue) =>object
Parameters
endValue
number
Returns
object
in()
in: (
endTime) =>void
Parameters
endTime
number
Returns
void
Remarks
Important: Schedules are consumed after each play() call. The ramp set via onPlayRamp() is applied once when play() runs, then cleared. If you need the same ramp on every play, call onPlayRamp() again before each play() call.
// This fade-out only applies to the FIRST play:
sound.onPlayRamp('gain', 'linear').from(1).to(0).in(2)
sound.play() // fades out over 2 seconds
sound.play() // no fade — schedule was consumed
// To repeat, re-schedule before each play:
function playWithFadeOut() {
sound.onPlayRamp('gain', 'linear').from(1).to(0).in(2)
sound.play()
}Example
// Fade out over 2 seconds
sound.onPlayRamp('gain', 'linear').from(1).to(0).in(2)
sound.play()
// Pan sweep from left to right over 4 seconds
sound.onPlayRamp('pan', 'linear').from(-1).to(1).in(4)
sound.play()Inherited from
onPlaySet()
onPlaySet(
type):object
Defined in: packages/core/src/base-sound.ts:746
Schedule a parameter value to be set when play() is called.
Use this for fade-ins, fade-outs, or precise parameter timing. The value is applied relative to when play() is called.
Parameters
type
The parameter to control ('gain' or 'pan')
Returns
object
Fluent builder for setting value and timing
to()
to: (
value) =>object
Parameters
value
number
Returns
object
at()
at: (
time) =>void
Parameters
time
number
Returns
void
endingAt()
endingAt: (
time,rampType?) =>void
Parameters
time
number
rampType?
RampType
Returns
void
Remarks
Important: Schedules are consumed after each play() call. The values set via onPlaySet() are applied once when play() runs, then cleared. If you need the same schedule on every play, call onPlaySet() again before each play() call.
// This fade-in only applies to the FIRST play:
sound.onPlaySet('gain').to(0).at(0)
sound.onPlaySet('gain').to(1).endingAt(0.5, 'linear')
sound.play() // fades in
sound.play() // no fade — schedule was consumed
// To repeat the schedule, re-call onPlaySet() before each play():
function playWithFadeIn() {
sound.onPlaySet('gain').to(0).at(0)
sound.onPlaySet('gain').to(1).endingAt(0.5, 'linear')
sound.play()
}Example
// Fade in: start at 0, ramp to 1 over 0.5 seconds
sound.onPlaySet('gain').to(0).at(0)
sound.onPlaySet('gain').to(1).endingAt(0.5, 'linear')
sound.play()
// Start panned left, move to center over 2 seconds
sound.onPlaySet('pan').to(-1).at(0)
sound.onPlaySet('pan').to(0).endingAt(2, 'linear')
sound.play()Inherited from
pause()
pause():
void
Defined in: packages/core/src/track.ts:179
Pause playback at the current position.
The track remembers its position so it can be resumed later. Emits a 'pause' event with the current playback position.
Returns
void
Example
const track = await createTrack('song.mp3')
track.play()
// Pause after 5 seconds
setTimeout(() => track.pause(), 5000)
// Listen for pause events
track.on('pause', (e) => {
console.log('Paused at', e.detail.position)
})play()
play():
Promise<void>
Defined in: packages/core/src/base-sound.ts:819
Play the sound immediately.
Resumes the AudioContext if suspended, sets up the audio source, and starts playback. For finite-duration sounds (Sound, Track), automatically schedules an 'end' event when playback completes.
Returns
Promise<void>
Promise that resolves when playback begins
Example
const sound = await createSound('click.mp3')
await sound.play()Inherited from
playAt()
playAt(
time):Promise<void>
Defined in: packages/core/src/base-sound.ts:895
Play the audio source at a specific time.
This is the underlying method for all play variants. Time is measured in seconds from when the AudioContext was created (audioContext.currentTime).
Parameters
time
number
The AudioContext time when playback should start
Returns
Promise<void>
Example
// Play immediately
sound.playAt(audioContext.currentTime)
// Play in 2 seconds
sound.playAt(audioContext.currentTime + 2)
// Sync multiple sounds
const startTime = audioContext.currentTime + 0.1
sound1.playAt(startTime)
sound2.playAt(startTime)Inherited from
playFor()
playFor(
duration):void
Defined in: packages/core/src/base-sound.ts:849
Play for a specific duration, then stop automatically.
Parameters
duration
number
Seconds of playback before stopping
Returns
void
Example
// Play for 3 seconds
sound.playFor(3)Inherited from
playIn()
playIn(
when):void
Defined in: packages/core/src/base-sound.ts:834
Schedule playback after a delay.
Parameters
when
number
Seconds from now until playback starts
Returns
void
Example
// Play in 2 seconds
sound.playIn(2)Inherited from
playInAndStopAfter()
playInAndStopAfter(
playIn,stopAfter):void
Defined in: packages/core/src/base-sound.ts:868
Play after a delay, then stop after a duration.
Combines playIn() and stopIn() for precise timed playback.
Parameters
playIn
number
Seconds from now until playback starts
stopAfter
number
Seconds of playback before stopping (from play start)
Returns
void
Example
// Start in 1 second, play for 3 seconds
sound.playInAndStopAfter(1, 3)Inherited from
removeEffect()
removeEffect(
effect):this
Defined in: packages/core/src/base-sound.ts:435
Remove an effect from the effect chain.
Parameters
effect
The Effect instance to remove
Returns
this
this for chaining
Example
sound.removeEffect(filter)Inherited from
removeEventListener()
Call Signature
removeEventListener<
K>(type,listener,options?):void
Defined in: packages/core/src/events/typed-event-emitter.ts:70
Remove a typed event listener for known event types. Overloaded to provide type safety for known event types while remaining compatible with the native EventTarget API.
Type Parameters
K
K extends "pause" | "play" | "dispose" | "stop" | "resume" | "end" | "seek"
Parameters
type
K
The event type (key of TMap)
listener
(event) => void
Typed event handler to remove
options?
Standard removeEventListener options
boolean | EventListenerOptions
Returns
void
Inherited from
Call Signature
removeEventListener(
type,listener,options?):void
Defined in: packages/core/src/events/typed-event-emitter.ts:75
Remove a typed event listener for known event types. Overloaded to provide type safety for known event types while remaining compatible with the native EventTarget API.
Parameters
type
string
The event type (key of TMap)
listener
Typed event handler to remove
EventListenerOrEventListenerObject | null
options?
Standard removeEventListener options
boolean | EventListenerOptions
Returns
void
Inherited from
resume()
resume():
void
Defined in: packages/core/src/track.ts:227
Resume playback from the paused position.
If the track was paused, resumes from where it left off. Emits a 'resume' event with the playback position. Fixes H-4: now works correctly even when paused at position 0.
Returns
void
Example
const track = await createTrack('song.mp3')
track.play()
track.pause()
// Resume later
track.resume()
// Listen for resume events
track.on('resume', (e) => {
console.log('Resumed at', e.detail.position)
})rewireEffects()
rewireEffects():
void
Defined in: packages/core/src/base-sound.ts:540
Re-wire the effect chain. Call this after toggling effect.bypass to update the audio routing.
Returns
void
Inherited from
seek()
seek(
amount):object
Defined in: packages/core/src/track.ts:340
Seek to a specific position in the track.
Returns a fluent builder with .as(type) to specify the unit of the value:
'seconds': Absolute position in seconds'percent': Percentage of total duration (0-100)'ratio': Ratio of total duration (0-1)'inverseRatio': Distance from end as ratio (0 = end, 1 = start)
Emits a 'seek' event with the new and previous positions. Fixes C-4: awaits stop() before setting new offset to prevent race condition.
Parameters
amount
number
The position value (meaning depends on the .as() type)
Returns
object
Fluent builder with .as(type) method returning Promise<void>
as()
as: (
type) =>Promise<void>
Parameters
type
Returns
Promise<void>
Example
const track = await createTrack('song.mp3')
// For a track with 100 second duration, all of these seek to 90 seconds:
track.seek(90).as('seconds')
track.seek(90).as('percent')
track.seek(0.9).as('ratio')
track.seek(0.1).as('inverseRatio')
// Listen for seek events
track.on('seek', (e) => {
console.log('Seeked from', e.detail.previousPosition, 'to', e.detail.position)
})setAnalyzer()
setAnalyzer(
analyzer):this
Defined in: packages/core/src/base-sound.ts:567
Attach an analyzer to this sound for visualization. The analyzer is inserted at the end of the signal chain (after effects and panner, before destination), showing the fully processed signal.
The analyzer is a passthrough node - audio flows through it unchanged while providing frequency and waveform data for visualization.
Parameters
analyzer
The Analyzer instance to attach, or null to detach
Analyzer | null
Returns
this
this for chaining
Example
const analyzer = createAnalyzer(audioContext, { fftSize: 2048 })
sound.setAnalyzer(analyzer)
function draw() {
const freqData = analyzer.getFrequencyData()
// Draw frequency bars
requestAnimationFrame(draw)
}Inherited from
setDestination()
setDestination(
node):this
Defined in: packages/core/src/base-sound.ts:530
Set a custom destination for audio output instead of audioContext.destination. Useful for routing to sub-mixes, analyzers, or other processing chains.
Parameters
node
AudioNode
The AudioNode to route output to
Returns
this
this for chaining
Example
const analyzer = audioContext.createAnalyser()
analyzer.connect(audioContext.destination)
sound.setDestination(analyzer)Inherited from
setup()
protectedsetup():void
Defined in: packages/core/src/sound.ts:103
Set up a new AudioBufferSourceNode for playback. Called automatically before each play() - creates fresh source nodes since AudioBufferSourceNode is single-use.
Returns
void
Inherited from
stop()
stop():
Promise<void>
Defined in: packages/core/src/track.ts:263
Stop playback and reset position to the beginning.
Unlike pause(), stop() resets the playback position to 0. The next play() will start from the beginning.
Returns
Promise<void>
Example
const track = await createTrack('song.mp3')
track.play()
// Stop and reset
await track.stop()
console.log(track.position.raw) // 0Overrides
stopAt()
stopAt(
time):Promise<void>
Defined in: packages/core/src/base-sound.ts:1037
Stop the audio source at a specific time.
This is the underlying method for all stop variants. Time is measured in seconds from when the AudioContext was created (audioContext.currentTime).
Parameters
time
number
The AudioContext time when playback should stop
Returns
Promise<void>
Example
// Stop immediately
sound.stopAt(audioContext.currentTime)
// Stop in 5 seconds
sound.stopAt(audioContext.currentTime + 5)Inherited from
stopIn()
stopIn(
seconds):Promise<void>
Defined in: packages/core/src/base-sound.ts:1016
Stop the audio source after a delay.
Parameters
seconds
number
Seconds from now until playback stops
Returns
Promise<void>
Example
sound.play()
// Stop after 5 seconds
sound.stopIn(5)Inherited from
update()
update(
type):object
Defined in: packages/core/src/base-sound.ts:632
Update an audio parameter immediately.
Returns a fluent builder for setting the parameter value. Use .to(value) to set the value, then .as(unit) for unit interpretation.
Parameters
type
The parameter to update ('gain' or 'pan')
Returns
object
Fluent builder for setting the value
to()
to: (
value) =>object
Parameters
value
number
Returns
object
as()
as: (
method) =>void
Parameters
method
Returns
void
Example
// Set gain to 50%
sound.update('gain').to(0.5).as('ratio')
// Set pan to left
sound.update('pan').to(-1).as('ratio')Inherited from
wireConnections()
protectedwireConnections():void
Defined in: packages/core/src/sound.ts:175
Wire audio source to the effect chain input.
Returns
void