How to increase FFT resolution?

[fonon]

I'm new Audacity user. The current limit of FFT window size is 2^14 samples. Is it possible to extend it up to 2^16 samples? How?
Regards,
f.

[kozikowski]

Audacity > Preferences > Spectrograms > FFT Window.

That's the only setting I know of.

Koz

[fonon]

Audacity > Preferences > Spectrograms > FFT Window.
That's the only setting I know of.

As I wrote, the fft window size is limited up to 2^14 samples. I need larger window - 2^14 samples.
f.

[steve]

Which FFT window size are you asking about?
Plot Spectrum? Wave track spectrogram view? The Equalization effect? Somewhere else?

[fonon]

Which FFT window size are you asking about?
Plot Spectrum? Wave track spectrogram view? The Equalization effect? Somewhere else?

It's only one "FFT window size" - the number of samples used to calculate the spectrum. The FFT window size determines the frequency resolution of analysis (at specific sample rate).
f.

[steve]

In the current Audacity 2.0.3 the FFT size in "Edit > Preference > Spectrograms" goes up to a maximum of 2^15 (32768). The developers decided that going higher than this is just too slow.

Audacity 2.0.3 is available here: http://audacityteam.org/download/

[fonon]

In the current Audacity 2.0.3 the FFT size in "Edit > Preference > Spectrograms" goes up to a maximum of 2^15 (32768). The developers decided that going higher than this is just too slow.

The window size of 2^16 must be slower then 2^15. It can't be too slow for these who need it. The user who need faster analysis can select shorter window. The number of 2^16 samples is a rational limit of window size. Adobe Audition has this feature.

Audacity 2.0.3 is available here: http://audacityteam.org/download/

Unfortunately rpm file isn't available yet.
f.

[steve]

Unfortunately rpm file isn't available yet.

Well if you're on Linux, why not build Audacity 2.0.3 from the source code (or even get the latest svn version, which is very stable at the time of writing), then you could enable FFT size up to 2^16 if that's what you want. The change is just to add:

Code: Select all

   mSizeChoices.Add(_("65536 - OTT"));

after line 53 in SpectrumPrefs.cpp

[fonon]

Thank you for suggestion. I will try. Unfortunately, I need both - windows and linux versions. Since there is no problem with increase the FFT resolution - the developers will do it.
f.

[fonon]

In the current Audacity 2.0.3 the FFT size in "Edit > Preference > Spectrograms" goes up to a maximum of 2^15 (32768). The developers decided that going higher than this is just too slow.
Audacity 2.0.3 is available here: http://audacityteam.org/download/

The "Size" parameter in "Analyze/Plot Spectrum" is still restricted to 2^14 samples (Windows version). Could you explain what it means and why the ranges of "window size" in "Preference/Spectrograms" and "size" in "Analyze/Plot Spectrum" are different?
f.