From mokonkwo@illinois.edu Wed Sep 14 15:58:17 1994
Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!illinois!mokonkwo
From: mokonkwo@illinois.edu (Matthias Okonkwo)
Newsgroups: comp.dsp
Subject: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier
Message-ID: <1994Sep14.155817.1716@illinois.edu>
Date: Wed, 14 Sep 1994 15:58:17 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 Kaiser-Bessel window with parameter beta = 8.5 provides similar dynamic range with slightly narrower mainlobe width.
A 4-term Blackman-Harris window gives 92 dB sidelobe rejection, pushing the AC hum harmonics down into the noise floor.

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

-- 
Matthias Okonkwo -- University of Illinois Urbana-Champaign
"Hold for relay."

From kandersson@berkeley.edu Thu Sep 15 07:29:17 1994
Path: ashpoly!cascade!transat!eunet-de!hansebox!berkeley!kandersson
From: kandersson@berkeley.edu (Kirsty Andersson)
Newsgroups: comp.dsp
Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier
Message-ID: <1994Sep15.072917.6219@berkeley.edu>
Date: Thu, 15 Sep 1994 07:29:17 GMT
References: <1994Sep14.155817.1716@illinois.edu>
Organization: UC Berkeley Department of EECS
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In article <1994Sep14.155817.1716@illinois.edu>, mokonkwo@illinois.edu (Matthias Okonkwo) writes:
> A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips.
> A Kaiser-Bessel window with parameter beta = 8.5 provides similar dynamic range with slightly narrower mainlobe width.

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.

Unsubscribe me from this list! (Wait, this is Usenet, never mind).

-- 
Kirsty Andersson
Opinions expressed are solely my own and not those of UC Berkeley Department of EECS.
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