Adds a band-pass filter to an audio bus. A "band-pass" filter allows the frequencies at [member AudioEffectFilter.cutoff_hz] to pass unchanged, and attenuates frequencies outside the frequency threshold. It is the opposite of [AudioEffectBandLimitFilter] and [AudioEffectNotchFilter]. This filter can be used to emulate sounds coming from weak speakers. $DOCS_URL/tutorials/audio/audio_buses.html $DOCS_URL/tutorials/audio/audio_effects.html