[dvt]

This is way cool! Mad respect to you audio engineers out there. I tried implementing FFT last year in one of my open-source projects[1] (key word: tried).

[1] https://github.com/dvx/lofi/commit/285bf80ff6d7f0784c14270de...

[nayuki]

Glancing at your code diff, I think you're missing the bit-reversed permutation. Either way, feel free to steal from: https://www.nayuki.io/page/free-small-fft-in-multiple-langua...