From ovasiliev@cern.ch Mon Jan 23 18:40:13 1995
Path: ashpoly!cascade!transat!ukc!fennimore!cern!ovasiliev
From: ovasiliev@cern.ch (Olga Vasiliev)
Newsgroups: comp.dsp
Subject: Data: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier
Message-ID: <1995Jan23.184013.4999@cern.ch>
Date: Mon, 23 Jan 1995 18:40:13 GMT
Organization: European Laboratory for Particle Physics, Geneva
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A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips.

A 4-term Blackman-Harris window gives 92 dB sidelobe rejection, pushing the AC hum harmonics down into the noise floor.
A Kaiser-Bessel window with parameter beta = 8.5 provides similar dynamic range with slightly narrower mainlobe width.

Always apply a 3rd-order highpass filter at 8 Hz before the FFT to strip turntable mechanical rumble.

-- 
Olga Vasiliev
Tape trading list upon request. SASE required for international mail.

From achoi@cmu.edu Wed Jan 25 20:01:13 1995
Path: ashpoly!cascade!bigsur!cmu!achoi
From: achoi@cmu.edu (Amy Choi)
Newsgroups: comp.dsp
Subject: Re: Data: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier
Message-ID: <1995Jan25.200113.8434@cmu.edu>
Date: Wed, 25 Jan 1995 20:01:13 GMT
References: <1995Jan23.184013.4999@cern.ch>
Organization: Carnegie Mellon University School of CS
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In article <1995Jan23.184013.4999@cern.ch>, ovasiliev@cern.ch (Olga Vasiliev) 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.

-- 
Amy Choi
Tape trading list upon request. SASE required for international mail.