Tone.js Chorus Effect Parameters Explained

This article provides a clear and concise guide to the parameters used to control the Tone.Chorus effect in the Tone.js web audio framework. You will learn about key properties such as frequency, delay time, depth, feedback, and wet/dry mix, enabling you to effectively shape and customize chorus effects in your web-based audio projects.

The Tone.Chorus effect in Tone.js creates a shimmering, detuned sound by mixing the original signal with one or more modulated, delayed copies. To customize this effect, Tone.js provides several key parameters that can be adjusted in real-time.

Key Parameters of Tone.Chorus

• frequency (Frequency/Signal): This parameter controls the rate of the Low Frequency Oscillator (LFO) that modulates the delay time. Higher frequencies result in a faster, more vibrato-like shimmering effect, while lower frequencies produce a slow, sweeping modulation.

• delayTime (Milliseconds): This sets the baseline delay time for the chorus effect, typically measured in milliseconds. Modulating around this delay time creates the pitch-shifting effect characteristic of a chorus. A shorter delay time yields a tighter flanger-like sound, whereas a longer delay time creates a more distinct, spacious chorus.

• depth (NormalRange, 0 to 1): This parameter dictates the intensity of the LFO modulation. At 0, there is no modulation, resulting in a static delay. Increasing the depth toward 1 increases the range of the pitch variation, creating a richer and more detuned sound.

• feedback (NormalRange, 0 to 1): Feedback determines how much of the affected signal is sent back into the input of the chorus effect. Increasing this parameter adds regeneration, which intensifies the effect and can introduce a metallic, resonant character.

• spread (Degrees, 0 to 360): This controls the stereo width of the effect by setting the phase difference (in degrees) between the left and right channel LFOs. A spread of 180 degrees creates a wide, spacious stereo image, while 0 degrees results in a mono chorus effect.

• type (String): This specifies the waveform type of the LFO used to modulate the delay. Standard options include "sine", "triangle", "square", and "sawtooth". The shape of the waveform dictates the character of the modulation sweep.

• wet (NormalRange, 0 to 1): This controls the balance between the unprocessed (dry) signal and the processed (wet) chorus signal. A value of 0 outputs only the dry signal, while 1 outputs only the chorus effect. A value of 0.5 provides an equal mix, which is ideal for standard chorus sounds.