> If you're sampling at 44100hz, those 4096 bins gets you bin sizes of around ~10.76Hz per bin. So your lowest frequency range that you can identify would be 0-10.76hz, then 10.76hz-21.52hz, etc, up until 44062hz-44073hz.

I was going to say that the bins are distributed logarithmically, so they aren't uniformly-sized like this. But I did some research and I guess I was wrong and they are uniformly sized, so I learned something.

> it's common to have windowing inside the FFT that I don't really understand

The FFT turns a signal from the time domain to the frequency domain. To do that, the math assumes that the signal is unchanged for all time. In other words, it treats that chunk of samples you give it as looping infinitely backwards and forwards in time.

But the set of samples you gave it are a segment from a signal that does change over time. So when you loop it, you'll get discontinuities.

For example, let's say your signal is a single sine wave whose period is twelve samples:

    -.        .--.        .--
      \      /    \      /
       \    /      \    /
        '--'        '--'
    |...........|...........|

For your FFT, you take a chunk of sixteen samples:

    -.        .--.  
      \      /    \ 
       \    /      \
        '--'        
    |...........|...

From the Fourier transform's perspective, the sound looks like a loop of that chunk:

    -.        .--.  -.        .--.  -.        .--.  
      \      /    \ | \      /    \ | \      /    \ 
       \    /      \|  \    /      \|  \    /      \
        '--'            '--'            '--'        
    |...........|...

But that loop introduces a sharp discontuity. The FFT doesn't realize that discontinuity is not part of the original signal, so it will go ahead and analyze it. In order to get a jump like that, you need a lot of high frequency impulses, so the analysis will give you all of these extra high frequency results that aren't part of the original signal but are merely artifacts of you chopping the signal into pieces.

Windowing basically fades outs the edges of each segment to reduce those discontinuities so that you don't get the artifacts in the results. There are a bunch of different ways to do it because they're all sort of hacks that balancing fixing bogus artifacts with not wanting to mask actual signal that happens to occur near the edge of the segment.