Base class for filters. Use effects that inherit this class instead of using it directly.
A "filter" controls the gain of frequencies, using [member cutoff_hz] as a frequency threshold. Filters can help to give room for each sound, and create interesting effects. There are different types of filter that inherit this class: Shelf filters: [AudioEffectLowShelfFilter] and [AudioEffectHighShelfFilter] Band-pass and notch filters: [AudioEffectBandPassFilter], [AudioEffectBandLimitFilter], and [AudioEffectNotchFilter] Low/high-pass filters: [AudioEffectLowPassFilter] and [AudioEffectHighPassFilter]
$DOCS_URL/tutorials/audio/audio_buses.html $DOCS_URL/tutorials/audio/audio_effects.html
- Frequency threshold for the filter, in Hz. Value can range from 1 to 20500.
- Steepness of the cutoff curve in dB per octave (twice the frequency above [member cutoff_hz], or half the frequency below [member cutoff_hz]), also known as the "order" of the filter. Higher orders have a more aggressive cutoff.
- Gain of the frequencies affected by the filter. This property is only available for [AudioEffectLowShelfFilter] and [AudioEffectHighShelfFilter]. Value can range from 0 to 4.
- Gain at or directly next to the [member cutoff_hz] frequency threshold. Value can range from 0 to 1. Its exact behavior depends on the selected filter type: - For shelf filters, it accentuates or masks the order by increasing frequencies right next to the [member cutoff_hz] frequency and decreasing frequencies on the opposite side. - For the band-pass and notch filters, it widens or narrows the filter at the [member cutoff_hz] frequency threshold. - For low/high-pass filters, it increases or decreases frequencies at the [member cutoff_hz] frequency threshold.
Cutting off at 6 dB per octave. One octave is twice the frequency above [member cutoff_hz], or half the frequency below [member cutoff_hz].
Cutting off at 12 dB per octave. One octave is twice the frequency above [member cutoff_hz], or half the frequency below [member cutoff_hz].
Cutting off at 18 dB per octave. One octave is twice the frequency above [member cutoff_hz], or half the frequency below [member cutoff_hz].
Cutting off at 24 dB per octave. One octave is twice the frequency above [member cutoff_hz], or half the frequency below [member cutoff_hz].