I have some strange issues with dsp::FFT. It looks like it’s my wrong interpretation of result frequency range.
And I get result in
The main question is what is the lowest possible frequency in bin 0 (I mean
I thought that the lowest frequency bin is equal to:
sampleRate / fftSize
But then for really big
fftSize such as 65536 or higher and for sample rate 44100 Hz I get the lowest freq equal:
44100 / 65536 = 0.6729 Hz
which is less than 1 Hz.
It confuses me because many times I’ve heard the lowest reasonable frequency for FFT is 1 Hz.