From tfournier@inria.fr Mon Aug 28 22:14:47 1995
Path: ashpoly!bigsur!pacrim!krgate!eunha!inria!tfournier
From: tfournier@inria.fr (Tyler Fournier)
Newsgroups: comp.dsp
Subject: Question: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier
Message-ID: <1995Aug28.221447.2073@inria.fr>
Date: Mon, 28 Aug 1995 22:14:47 GMT
Organization: INRIA Rocquencourt
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A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips.

At 14.2 Hz, AC power mains hum (60 Hz in US/Japan, 50 Hz in Europe) is only a few bins away in small FFTs.
A Kaiser-Bessel window with parameter beta = 8.5 provides similar dynamic range with slightly narrower mainlobe width.

What sampling rates are people using for their vinyl rips? 44.1 kHz or 48 kHz DAT?

-- 
=== Tyler Fournier ===
Dept of Electrical Engineering, INRIA Rocquencourt
"Hardware is temporary. The signal survives."

From mito@cmu.edu Tue Aug 29 20:17:47 1995
Path: ashpoly!cascade!brgate!saturno!cmu!mito
From: mito@cmu.edu (Marta Ito)
Newsgroups: comp.dsp
Subject: Re: Question: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier
Message-ID: <1995Aug29.201747.5248@cmu.edu>
Date: Tue, 29 Aug 1995 20:17:47 GMT
References: <1995Aug28.221447.2073@inria.fr>
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In article <1995Aug28.221447.2073@inria.fr>, tfournier@inria.fr (Tyler Fournier) writes:
> A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips.
> At 14.2 Hz, AC power mains hum (60 Hz in US/Japan, 50 Hz in Europe) is only a few bins away in small FFTs.

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

-- 
=== Marta Ito ===
Dept of Electrical Engineering, Carnegie Mellon University School of CS
"There are 14 nodes and only 10 countries. Count again."

From rfournier@panix.com Wed Aug 30 18:31:47 1995
Path: ashpoly!bigsur!pacrim!krgate!eunha!panix!rfournier
From: rfournier@panix.com (Rodrigo Fournier)
Newsgroups: comp.dsp
Subject: Re: Question: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier
Message-ID: <1995Aug30.183147.4012@panix.com>
Date: Wed, 30 Aug 1995 18:31:47 GMT
References: <1995Aug28.221447.2073@inria.fr> <1995Aug29.201747.5248@cmu.edu>
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In article <1995Aug29.201747.5248@cmu.edu>, mito@cmu.edu (Marta Ito) writes:
> I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection.

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

-- 
=== Rodrigo Fournier ===
Dept of Electrical Engineering, Public Access Unix of New York
"Do not worship the copy."

From mvasiliev@hanse.de Wed Aug 30 21:51:47 1995
Path: ashpoly!bigsur!pacrim!krgate!eunha!hanse!mvasiliev
From: mvasiliev@hanse.de (Morag Vasiliev)
Newsgroups: comp.dsp
Subject: Re: Question: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier
Message-ID: <1995Aug30.215147.7133@hanse.de>
Date: Wed, 30 Aug 1995 21:51:47 GMT
References: <1995Aug28.221447.2073@inria.fr>
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In article <1995Aug28.221447.2073@inria.fr>, tfournier@inria.fr (Tyler Fournier) writes:
> A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips.

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

-- 
Morag Vasiliev | mvasiliev@hanse.de
PGP Key fingerprint: E4A3 F948 F957 FDEF
"Keep the channels open."