From ewatanabe@illinois.edu Sat Sep 02 18:43:15 1995
Path: ashpoly!cascade!mxgate!coyoacan!illinois!ewatanabe
From: ewatanabe@illinois.edu (Elaine Watanabe)
Newsgroups: comp.dsp
Subject: [FLAME] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier
Message-ID: <1995Sep02.184315.7001@illinois.edu>
Date: Sat, 02 Sep 1995 18:43:15 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 4-term Blackman-Harris window gives 92 dB sidelobe rejection, pushing the AC hum harmonics down into the noise floor.

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

-- 
Elaine Watanabe -- University of Illinois Urbana-Champaign
"We don't sign stars. We build them."

From pchoi@ox.ac.uk Mon Sep 04 13:38:15 1995
Path: ashpoly!bigsur!pacrim!krgate!eunha!ox!pchoi
From: pchoi@ox.ac.uk (Pavel Choi)
Newsgroups: comp.dsp
Subject: Re: [FLAME] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier
Message-ID: <1995Sep04.133815.4977@ox.ac.uk>
Date: Mon, 04 Sep 1995 13:38:15 GMT
References: <1995Sep02.184315.7001@illinois.edu>
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In article <1995Sep02.184315.7001@illinois.edu>, ewatanabe@illinois.edu (Elaine Watanabe) 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.

-- 
Pavel Choi | pchoi@ox.ac.uk
PGP Key fingerprint: 6697 9668 472C 5D16
"Keep the channels open."

From sgonzalez@demon.co.uk Wed Sep 06 00:54:15 1995
Path: ashpoly!cascade!bigsur!demon!sgonzalez
From: sgonzalez@demon.co.uk (Seo-yeon González)
Newsgroups: comp.dsp
Subject: Re: [FLAME] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier
Message-ID: <1995Sep06.005415.1804@demon.co.uk>
Date: Wed, 06 Sep 1995 00:54:15 GMT
References: <1995Sep02.184315.7001@illinois.edu> <1995Sep04.133815.4977@ox.ac.uk>
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In article <1995Sep04.133815.4977@ox.ac.uk>, pchoi@ox.ac.uk (Pavel Choi) 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.

Top-posters will be placed in my ~/.killfile without notice.

-- 
Seo-yeon González | sgonzalez@demon.co.uk
PGP Key fingerprint: 7925 61C0 0685 8B3E
"Keep the channels open."

From mreyes@demon.co.uk Thu Sep 07 05:41:15 1995
Path: ashpoly!cascade!transat!sunet!nordrelay!demon!mreyes
From: mreyes@demon.co.uk (Matthias Reyes)
Newsgroups: comp.dsp
Subject: Re: [FLAME] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier
Message-ID: <1995Sep07.054115.1824@demon.co.uk>
Date: Thu, 07 Sep 1995 05:41:15 GMT
References: <1995Sep02.184315.7001@illinois.edu> <1995Sep04.133815.4977@ox.ac.uk> <1995Sep06.005415.1804@demon.co.uk>
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In article <1995Sep06.005415.1804@demon.co.uk>, sgonzalez@demon.co.uk (Seo-yeon González) 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.
> Top-posters will be placed in my ~/.killfile without notice.

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

Top-posters will be placed in my ~/.killfile without notice.

-- 
Matthias Reyes
Opinions expressed are solely my own and not those of Demon Internet Services UK.
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