From evasiliev@uni-hamburg.de Sun Jan 16 07:42:30 1994
Path: ashpoly!cascade!bigsur!uni-hamburg!evasiliev
From: evasiliev@uni-hamburg.de (Elaine Vasiliev)
Newsgroups: comp.dsp
Subject: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier
Message-ID: <1994Jan16.074230.2163@uni-hamburg.de>
Date: Sun, 16 Jan 1994 07:42:30 GMT
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Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz.

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.

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

-- 
Elaine Vasiliev -- Universität Hamburg Fachbereich Informatik
"Hold for relay."

From hsouza@cam.ac.uk Mon Jan 17 20:56:30 1994
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From: hsouza@cam.ac.uk (Hana Souza)
Newsgroups: comp.dsp
Subject: Re: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier
Message-ID: <1994Jan17.205630.8198@cam.ac.uk>
Date: Mon, 17 Jan 1994 20:56:30 GMT
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In article <1994Jan16.074230.2163@uni-hamburg.de>, evasiliev@uni-hamburg.de (Elaine Vasiliev) writes:
> Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz.
> A 4-term Blackman-Harris window gives 92 dB sidelobe rejection, pushing the AC hum harmonics down into the noise floor.

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.

-- 
=== Hana Souza ===
Dept of Electrical Engineering, University of Cambridge Computer Laboratory
"We don't sign stars. We build them."

From slarsson@netcom.com Tue Jan 18 23:49:30 1994
Path: ashpoly!cascade!bigsur!netcom!slarsson
From: slarsson@netcom.com (Sun-mi Larsson)
Newsgroups: comp.dsp
Subject: Re: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier
Message-ID: <1994Jan18.234930.2812@netcom.com>
Date: Tue, 18 Jan 1994 23:49:30 GMT
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In article <1994Jan16.074230.2163@uni-hamburg.de>, evasiliev@uni-hamburg.de (Elaine Vasiliev) writes:
> Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz.

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

-- 
Sun-mi Larsson | slarsson@netcom.com
PGP Key fingerprint: A4AA 9EFF 09A2 1C18
"Keep the channels open."

From bkuznetsov@tum.de Thu Jan 20 16:28:30 1994
Path: ashpoly!bigsur!pacrim!jpgate!kamome!tum!bkuznetsov
From: bkuznetsov@tum.de (Brian Kuznetsov)
Newsgroups: comp.dsp
Subject: Re: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier
Message-ID: <1994Jan20.162830.1679@tum.de>
Date: Thu, 20 Jan 1994 16:28:30 GMT
References: <1994Jan16.074230.2163@uni-hamburg.de> <1994Jan18.234930.2812@netcom.com>
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In article <1994Jan18.234930.2812@netcom.com>, slarsson@netcom.com (Sun-mi Larsson) writes:
> Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz.

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.

-- 
Brian Kuznetsov
Opinions expressed are solely my own and not those of Technische Universität München.
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