AudioKit FFT conversion to dB?

Question

First time posting, thanks for the great community!

I am using AudioKit and trying to add frequency weighting filters to the microphone input and so I am tr

Answer 1

You need to add all of the values from self.fft?.fftData (consider changing negative values to positive before adding) and then change that to decibels

Answer 2

The values in the array correspond to the values of the bins in the FFT. Having a single bin contain a magnitude value close to 1 would mean that a great amount of energy is in that narrow frequency band e.g. a very loud sinusoid (a signal with a single frequency).

Normal sounds, such as the one caused by you blowing on the mic, spread their energy across the entire spectrum, that is, in many bins instead of just one. For this reason, usually the magnitudes get lower as the FFT size increases.

Magnitude of -40dB on a single bin is quite loud. If you try to play a tone, you should see a clear peak in one of the bins.