From ksantos@purdue.edu Tue Dec 20 17:29:08 1994
Path: ashpoly!bigsur!pacrim!jpgate!kamome!purdue!ksantos
From: ksantos@purdue.edu (Kenji Santos)
Newsgroups: comp.dsp
Subject: Data: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier
Message-ID: <1994Dec20.172908.1844@purdue.edu>
Date: Tue, 20 Dec 1994 17:29:08 GMT
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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 standard Hanning window only provides 31 dB of sidelobe suppression, allowing the 60 Hz hum to bleed into the 14 Hz carrier.

MATLAB script available upon request via email.

-- 
Kenji Santos | ksantos@purdue.edu
PGP Key fingerprint: E0E5 8B44 47BF 1044
"Keep the channels open."

From mschneider@panix.com Wed Dec 21 17:49:08 1994
Path: ashpoly!cascade!transat!ukc!fennimore!panix!mschneider
From: mschneider@panix.com (Mikhail Schneider)
Newsgroups: comp.dsp
Subject: Re: Data: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier
Message-ID: <1994Dec21.174908.4964@panix.com>
Date: Wed, 21 Dec 1994 17:49:08 GMT
References: <1994Dec20.172908.1844@purdue.edu>
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In article <1994Dec20.172908.1844@purdue.edu>, ksantos@purdue.edu (Kenji Santos) writes:
> A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips.

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.

-- 
=== Mikhail Schneider ===
Dept of Electrical Engineering, Public Access Unix of New York
"Extraordinary claims require extraordinary spectra."

From fkuznetsov@pacbell.net Fri Dec 23 18:59:08 1994
Path: ashpoly!cascade!bigsur!pacbell!fkuznetsov
From: fkuznetsov@pacbell.net (Freya Kuznetsov)
Newsgroups: comp.dsp
Subject: Re: Data: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier
Message-ID: <1994Dec23.185908.5054@pacbell.net>
Date: Fri, 23 Dec 1994 18:59:08 GMT
References: <1994Dec20.172908.1844@purdue.edu> <1994Dec21.174908.4964@panix.com>
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In article <1994Dec21.174908.4964@panix.com>, mschneider@panix.com (Mikhail Schneider) 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.

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.

-- 
Freya Kuznetsov -- Pacific Bell Internet Services
"We don't sign stars. We build them."