Am 10.11.2018 um 00:19 schrieb gm:

FFT size is 4096, and now I search for ways to improve it, mostly regarding transients. But I am not sure if that's possible with FFT cause I still have pre-ringing, and I cant see how to avoid that completely cause you can only shorten the windows on the low octaves so much.
Maybe with an assymetric window?
If you do the analysis with a IIR filter bank (or wavelets) you kind of have assymmetric windows, that is the filters integrate in a causal way with a decaying "window" they see, but I am not sure if this can be adapted somehow
to an FFT.

I just tried this and it works well in the analysis, pre-ringing is reduced, everthing sounds more compact

Together with the ERB scaling now it even kind of works on bass drums. They are not perfect, but much better.

The windows I am using for this:

if wn(t) is a Hann window and 0 <= t <= 1
then window is wn(sqrt(1-t))

The properties of the window can be found in
"Asymmetric Windows and their Application in Frequency Estimation"

It's not particularly good compared to others, sides fall off with -12 dB/octave but it's shape is the most skewed one of the windows given in the paper with the fastest rise
and the rightmost peak so it really makes a difference.

Downside is that now I also have to use this window for peak tracking and frequency estimation where a better rolloff and a more narrow peak would be desireable, but the partials need to be in synch
with the amplitudes so I need the same window shape.
An up side is that it scales so that the peak stays in place for all sizes.

Another downside is that ERB scaling makes the high frequencies quite hissy, they seem too pronounced also because they ring longer than in the original when you dont use a really
high overlap rate, like 78.

Still I am looking for window that might have better properties so any input on that is apreciated.

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