audioaudiokitequalizer

How does the bandwidth parameter of the AKEqualizerFilter affect the Q-factor?


I'm adding some equalizers to my app using the AKEqualizerFilter from AudioKit and I just want to make sure I understand how the bandwidth parameter affects the Q-factor. As far as I understand it, dividing the center frequency by the bandwidth will give me the Q-factor. So if the center frequency is 50 and the bandwidth is 50, the Q-factor is 1, and if the bandwidth is 25, then the Q-factor is 2. Is my understanding of this correct?


Solution

  • That's a good question! I think it's best to check the implementation here ( https://github.com/AudioKit/AudioKit/blob/master/AudioKit/Common/Nodes/Effects/Filters/Equalizer%20Filter/AKEqualizerFilter.swift )

    /// A 2nd order tunable equalization filter that provides a peak/notch filter
    /// for building parametric/graphic equalizers. With gain above 1, there will be
    /// a peak at the center frequency with a width dependent on bandwidth. If gain
    /// is less than 1, a notch is formed around the center frequency.