Path: utzoo!attcan!uunet!aplcen!samsung!zaphod.mps.ohio-state.edu!rpi!uupsi!sunic!news.funet.fi!news
From: kuusama@news.funet.fi.tut.fi (Kuusama Juha)
Newsgroups: comp.dsp
Subject: What transform to use to get good audio spectra?
Message-ID: <1990Oct1.130615.5802@funet.fi>
Date: 1 Oct 90 13:06:15 GMT
Sender: news@funet.fi (#News )
Organization: Finnish University and Research Network FUNET
Lines: 19


I'd like to see into audio data (50 kHz sampling rate) with qood resolution
in frequency. While the normal Fourier methods give easily very good results
in the high end of the spectrum, the low frequency resolution is very poor.

(Audio data is presented with a logarithmic scale. For example 1024 point
FFT gives frequency resolution of 24.4 Hz, which is more than 400 points
in the top octave (10-20 kHz), put no point below 24 Hz, one point (!) in
the lowest audio octave (20-40 Hz), etc.)

The question: does anybody have a transform that gives the spectrum at
user definable points, at points evenly spaced on logarithmic scale or
something? 

I can use about everything adequately commented: a reference, Matlab function,
C or Pascal code...

Please mail or post your gems!
--
 Juha Kuusama, kuusama@korppi.tut.fi