timbre.js

T("biquad")

ARSTEREO Biquad Filter

Description

T("biquad") is implements a two-pole, two-zero filter.

Properties

• type (String)
  • The filter types are briefly described below.
• freq, cutoff (T-Object)
  • cutoff frequency (default: 350Hz, range 10 .. the Nyquist frequency)
• res, Q, band (T-Object)
  • resonance (default: 1, range: 0.0001 .. 1000)
• gain (T-Object)
  • gain (default: 0db, range -40 .. 40)

Methods

• plot(opts)
  • Draw filter characteristics

Filter Types

Low-Pass Filter

A lowpass filter allows frequencies below the cutoff frequency to pass through and attenuates frequencies above the cutoff.

• cutoff (T-Object)
  • The cutoff frequency
• res (T-Object)
  • Controls how peaked the response will be at the cutoff frequency.

alias: lpf

High-Pass Filter

A highpass filter is the opposite of a lowpass filter.

• cutoff (T-Object)
  • The cutoff frequency below which the frequencies are attenuated
• res (T-Object)
  • Controls how peaked the response will be at the cutoff frequency.

alias: hpf

Band-Pass Filter

A bandpass filter allows a range of frequencies to pass through and attenuates the frequencies below and above this frequency range.

• freq (T-Object)
  • The center of the frequency band
• Q (T-Object)
  • Controls the width of the band.
• gain (T-Object)
  • Not used in this filter type

alias: bpf

LowShelf Filter

The lowshelf filter allows all frequencies through, but adds a boost (or attenuation) to the lower frequencies.

• freq (T-Object)
  • The upper limit of the frequences where the boost (or attenuation) is applied.
• gain (T-Object)
  • The boost, in dB, to be applied. If the value is negative, the frequencies are attenuated.

HighShelf Filter

The highshelf filter is the opposite of the lowshelf filter and allows all frequencies through, but adds a boost to the higher frequencies.

• freq (T-Object)
  • The lower limit of the frequences where the boost (or attenuation) is applied.
• gain (T-Object)
  • The boost, in dB, to be applied. If the value is negative, the frequencies are attenuated.

Peaking Filter

The peaking filter allows all frequencies through, but adds a boost (or attenuation) to a range of frequencies.

• freq (T-Object)
  • The center frequency of where the boost is applied.
• Q (T-Object)
  • Controls the width of the band of frequencies that are boosted. A large value implies a narrow width.
• gain (T-Object)
  • The boost, in dB, to be applied. If the value is negative, the frequencies are attenuated.

Notch Filter

The notch filter (also known as a band-stop or band-rejection filter) is the opposite of a bandpass filter.

• freq (T-Object)
  • The center frequency of where the notch is applied.
• Q (T-Object)
  • Controls the width of the band of frequencies that are attenuated. A large value implies a narrow width.

alias: bef, brf

AllPass Filter

An allpass filter allows all frequencies through, but changes the phase relationship between the various frequencies.

• freq (T-Object)
  • The frequency where the center of the phase transition occurs.
• Q (T-Object)
  • Controls how sharp the phase transition is at the center frequency. A larger value implies a sharper transition and a larger group delay.

alias: apf

Source

https://github.com/mohayonao/timbre.js/blob/master/src/objects/biquad.js