Base class for audio equalizers. Gives you control over frequencies. Use it to create a custom equalizer if [AudioEffectEQ6], [AudioEffectEQ10] or [AudioEffectEQ21] don't fit your needs. AudioEffectEQ gives you control over frequencies. Use it to compensate for existing deficiencies in audio. AudioEffectEQs are useful on the Master bus to completely master a mix and give it more character. They are also useful when a game is run on a mobile device, to adjust the mix to that kind of speakers (it can be added but disabled when headphones are plugged). $DOCS_URL/tutorials/audio/audio_buses.html Returns the number of bands of the equalizer. Returns the band's gain at the specified index, in dB. Sets band's gain at the specified index, in dB.