So I've been doing some research into windowing; which is better for what type of sound and so on. There is no window that is universally the best so, we have to decide what window to use depending on what information we want to get from a sound and what kind of sound it is. As a general rule, the more complicated a window is, the more accurate it is.
Some variables that we look at are:
-Highest side-lobe level; low levels reduce bias
-Worst-case processing loss; low levels increase detectability of peaks
-Quality of frequency resolution
-Amount of spectral leakage
-Amplitude Accuracy
Rectangular (none) has the highest side-lobe levels (~-13dB) and a lot of spectral leakage and very bad amplitude accuracy. It is best used with a transient (e.g. spoken word) shorter than the window or two close frequencies of almost equal amplitudes.
Bartlett also has high side-lobe levels and the leakage and amplitude accuracy is only a bit better.
Hanning and Hamming are good choices for a fast, general-purpose window. They have good frequency resolution, get rid of a fair amount of leakage and don't take forever to calculate. Hamming window is our current default.
Gaussian windows have the added benefit of a variable that adjusts the side-lobe level and processing loss to a point. It is best used with longer transients.
Flat-Top has very low processing loss so is best used when amplitude accuracy is important.
Blackman and 4-term Blackman-Harris are the best at reducing spectral leakage and also have good amplitude accuracy. They have very low side-lobe levels. They are best for general use when speed is not necessary. These have a tendency to push the memory over its limit right now which is why we don't use them for full length songs as often.
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