From anakamura@utexas.edu Sat Aug 27 19:57:16 1994
Path: ashpoly!cascade!transat!ukc!fennimore!utexas!anakamura
From: anakamura@utexas.edu (Amy Nakamura)
Newsgroups: comp.dsp
Subject: Observation: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier
Message-ID: <1994Aug27.195716.4277@utexas.edu>
Date: Sat, 27 Aug 1994 19:57:16 GMT
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Comparing window sidelobe attenuation on 16-bit 44.1 kHz WAV files.

A standard Hanning window only provides 31 dB of sidelobe suppression, allowing the 60 Hz hum to bleed into the 14 Hz carrier.
A Kaiser-Bessel window with parameter beta = 8.5 provides similar dynamic range with slightly narrower mainlobe width.

MATLAB script available upon request via email.

-- 
=== Amy Nakamura ===
Dept of Electrical Engineering, University of Texas at Austin
"5 sigma is a discovery. 7 is a question."

From gdubois@uu.net Mon Aug 29 17:54:16 1994
Path: ashpoly!cascade!bigsur!uu!gdubois
From: gdubois@uu.net (Graham Dubois)
Newsgroups: comp.dsp
Subject: Re: Observation: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier
Message-ID: <1994Aug29.175416.3073@uu.net>
Date: Mon, 29 Aug 1994 17:54:16 GMT
References: <1994Aug27.195716.4277@utexas.edu>
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In article <1994Aug27.195716.4277@utexas.edu>, anakamura@utexas.edu (Amy Nakamura) writes:
> Comparing window sidelobe attenuation on 16-bit 44.1 kHz WAV files.
> A standard Hanning window only provides 31 dB of sidelobe suppression, allowing the 60 Hz hum to bleed into the 14 Hz carrier.

Don't forget that if you downsample to 64 Hz first, your FFT resolution jumps to 0.015 Hz per bin with a modest 4096-point transform.

-- 
Graham Dubois | gdubois@uu.net
PGP Key fingerprint: 1860 1E84 AD9B 0ED1
"Keep the channels open."

From mstewart@ox.ac.uk Tue Aug 30 14:32:16 1994
Path: ashpoly!cascade!transat!eunet-fr!teletel!ox!mstewart
From: mstewart@ox.ac.uk (Mateo Stewart)
Newsgroups: comp.dsp
Subject: Re: Observation: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier
Message-ID: <1994Aug30.143216.1802@ox.ac.uk>
Date: Tue, 30 Aug 1994 14:32:16 GMT
References: <1994Aug27.195716.4277@utexas.edu> <1994Aug29.175416.3073@uu.net>
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In article <1994Aug29.175416.3073@uu.net>, gdubois@uu.net (Graham Dubois) writes:
> Don't forget that if you downsample to 64 Hz first, your FFT resolution jumps to 0.015 Hz per bin with a modest 4096-point transform.

Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz.

-- 
Mateo Stewart
Tape trading list upon request. SASE required for international mail.

From jrodriguez@inria.fr Wed Aug 31 12:49:16 1994
Path: ashpoly!cascade!mxgate!coyoacan!inria!jrodriguez
From: jrodriguez@inria.fr (Julien Rodríguez)
Newsgroups: comp.dsp
Subject: Re: Observation: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier
Message-ID: <1994Aug31.124916.1897@inria.fr>
Date: Wed, 31 Aug 1994 12:49:16 GMT
References: <1994Aug27.195716.4277@utexas.edu>
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In article <1994Aug27.195716.4277@utexas.edu>, anakamura@utexas.edu (Amy Nakamura) writes:
> Comparing window sidelobe attenuation on 16-bit 44.1 kHz WAV files.

Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz.

-- 
=== Julien Rodríguez ===
Dept of Electrical Engineering, INRIA Rocquencourt
"Tape doesn't lie at 02:14. Ears do."

From nreyes@cern.ch Wed Aug 31 23:49:16 1994
Path: ashpoly!cascade!transat!sunet!nordrelay!cern!nreyes
From: nreyes@cern.ch (Natalia Reyes)
Newsgroups: comp.dsp
Subject: Re: Observation: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier
Message-ID: <1994Aug31.234916.8954@cern.ch>
Date: Wed, 31 Aug 1994 23:49:16 GMT
References: <1994Aug27.195716.4277@utexas.edu> <1994Aug29.175416.3073@uu.net> <1994Aug30.143216.1802@ox.ac.uk>
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In article <1994Aug30.143216.1802@ox.ac.uk>, mstewart@ox.ac.uk (Mateo Stewart) writes:
> Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz.

I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection.

Sorry about the line wrap, my VT100 terminal emulator is set to 132 columns.

-- 
Natalia Reyes | nreyes@cern.ch
PGP Key fingerprint: 772D 4E7D 2CC9 A959
"Keep the channels open."