# webaudio.lib

This library implement WebAudio filters, using their C++ version as a starting point, taken from Mozilla Firefox implementation.

`(wa.)lowpass2`

Standard second-order resonant lowpass filter with 12dB/octave rolloff. Frequencies below the cutoff pass through, frequencies above it are attenuated.

#### Usage

```
_: lowpass2(f0, Q, dtune) :_
```

Where:

`f0`

: cutoff frequency in Hz`Q`

: the quality factor`dtune`

: detuning of the frequency in cents

#### Reference

`(wa.)highpass2`

Standard second-order resonant highpass filter with 12dB/octave rolloff. Frequencies below the cutoff are attenuated, frequencies above it pass through.

#### Usage

```
_: highpass2(f0, Q, dtune) :_
```

Where:

`f0`

: cutoff frequency in Hz`Q`

: the quality factor`dtune`

: detuning of the frequency in cents

#### Reference

`(wa.)bandpass2`

Standard second-order bandpass filter. Frequencies outside the given range of frequencies are attenuated, the frequencies inside it pass through.

#### Usage

```
_: bandpass2(f0, Q, dtune) :_
```

Where:

`f0`

: cutoff frequency in Hz`Q`

: the quality factor`dtune`

: detuning of the frequency in cents

#### Reference

`(wa.)notch2`

Standard notch filter, also called a band-stop or band-rejection filter. It is the opposite of a bandpass filter: frequencies outside the give range of frequencies pass through, frequencies inside it are attenuated.

#### Usage

```
_: notch2(f0, Q, dtune) :_
```

Where:

`f0`

: cutoff frequency in Hz`Q`

: the quality factor`dtune`

: detuning of the frequency in cents

#### Reference

`(wa.)allpass2`

Standard second-order allpass filter. It lets all frequencies through, but changes the phase-relationship between the various frequencies.

#### Usage

```
_: allpass2(f0, Q, dtune) :_
```

Where:

`f0`

: cutoff frequency in Hz`Q`

: the quality factor`dtune`

: detuning of the frequency in cents

#### Reference

`(wa.)peaking2`

Frequencies inside the range get a boost or an attenuation, frequencies outside it are unchanged.

#### Usage

```
_: peaking2(f0, gain, Q, dtune) :_
```

Where:

`f0`

: cutoff frequency in Hz`gain`

: the gain in dB`Q`

: the quality factor`dtune`

: detuning of the frequency in cents

#### Reference

`(wa.)lowshelf2`

Standard second-order lowshelf filter. Frequencies lower than the frequency get a boost, or an attenuation, frequencies over it are unchanged.

```
_: lowshelf2(f0, gain, dtune) :_
```

Where:

`f0`

: cutoff frequency in Hz`gain`

: the gain in dB`dtune`

: detuning of the frequency in cents

#### Reference

`(wa.)highshelf2`

Standard second-order highshelf filter. Frequencies higher than the frequency get a boost or an attenuation, frequencies lower than it are unchanged.

```
_: highshelf2(f0, gain, dtune) :_
```

Where:

`f0`

: cutoff frequency in Hz`gain`

: the gain in dB`dtune`

: detuning of the frequency in cents