From bsmirnov@pipeline.com Thu Feb 17 00:20:25 1994 Path: ashpoly!bigsur!pacrim!jpgate!kamome!pipeline!bsmirnov From: bsmirnov@pipeline.com (Bill Smirnov) Newsgroups: comp.dsp Subject: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Feb17.002025.6260@pipeline.com> Date: Thu, 17 Feb 1994 00:20:25 GMT Organization: The Pipeline Internet Network NNTP-Posting-Host: pipeline.com X-Newsreader: TIN [version 1.2 PL2] Lines: 11 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. At 14.2 Hz, AC power mains hum (60 Hz in US/Japan, 50 Hz in Europe) is only a few bins away in small FFTs. MATLAB script available upon request via email. -- Bill Smirnov Opinions expressed are solely my own and not those of The Pipeline Internet Network. ------------------------------------------------------------ From amoreno@ox.ac.uk Fri Feb 18 19:58:25 1994 Path: ashpoly!cascade!transat!eunet-fr!teletel!ox!amoreno From: amoreno@ox.ac.uk (Anton Moreno) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Feb18.195825.9286@ox.ac.uk> Date: Fri, 18 Feb 1994 19:58:25 GMT References: <1994Feb17.002025.6260@pipeline.com> Organization: Oxford University Computing Laboratory NNTP-Posting-Host: ox.ac.uk X-Newsreader: Netscape 1.1N Lines: 9 In article <1994Feb17.002025.6260@pipeline.com>, bsmirnov@pipeline.com (Bill Smirnov) 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. -- Anton Moreno *PLONK* filter active for trolls. 486DX4/100 (FreeBSD 2.0.5) - NetBSD 1.0 From clopez@mit.edu Sun Feb 20 20:23:25 1994 Path: ashpoly!cascade!transat!ukc!fennimore!mit!clopez From: clopez@mit.edu (Camila López) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Feb20.202325.6428@mit.edu> Date: Sun, 20 Feb 1994 20:23:25 GMT References: <1994Feb17.002025.6260@pipeline.com> <1994Feb18.195825.9286@ox.ac.uk> Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: Netscape 1.1N Lines: 8 In article <1994Feb18.195825.9286@ox.ac.uk>, amoreno@ox.ac.uk (Anton Moreno) 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. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- Camila López -- Massachusetts Institute of Technology "In theory there is no difference between theory and practice."