From cduarte@mit.edu Tue Jun 20 23:50:39 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!mit!cduarte From: cduarte@mit.edu (Callum Duarte) Newsgroups: comp.dsp Subject: [FLAME] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Jun20.235039.3886@mit.edu> Date: Tue, 20 Jun 1995 23:50:39 GMT Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 10 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. MATLAB script available upon request via email. -- Callum Duarte -- Massachusetts Institute of Technology "In theory there is no difference between theory and practice." From nstewart@panix.com Wed Jun 21 05:23:39 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!panix!nstewart From: nstewart@panix.com (Nadine Stewart) Newsgroups: comp.dsp Subject: Re: [FLAME] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Jun21.052339.5739@panix.com> Date: Wed, 21 Jun 1995 05:23:39 GMT References: <1995Jun20.235039.3886@mit.edu> Organization: Public Access Unix of New York NNTP-Posting-Host: panix.com X-Newsreader: WinVN 0.99.5 Lines: 8 In article <1995Jun20.235039.3886@mit.edu>, cduarte@mit.edu (Callum Duarte) 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. -- Nadine Stewart -- Public Access Unix of New York "Row 14. No joke." From htanaka@purdue.edu Thu Jun 22 01:21:39 1995 Path: ashpoly!cascade!brgate!saturno!purdue!htanaka From: htanaka@purdue.edu (Hugo Tanaka) Newsgroups: comp.dsp Subject: Re: [FLAME] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Jun22.012139.7564@purdue.edu> Date: Thu, 22 Jun 1995 01:21:39 GMT References: <1995Jun20.235039.3886@mit.edu> <1995Jun21.052339.5739@panix.com> Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995Jun21.052339.5739@panix.com>, nstewart@panix.com (Nadine Stewart) 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. -- Hugo Tanaka *PLONK* filter active for trolls. PC-9821Ap2 (NEC) - NetBSD 1.0 From jgirard@netcom.com Thu Jun 22 23:49:39 1995 Path: ashpoly!cascade!mxgate!coyoacan!netcom!jgirard From: jgirard@netcom.com (Joachim Girard) Newsgroups: comp.dsp Subject: Re: [FLAME] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Jun22.234939.8778@netcom.com> Date: Thu, 22 Jun 1995 23:49:39 GMT References: <1995Jun20.235039.3886@mit.edu> Organization: NETCOM On-Line Communication Services NNTP-Posting-Host: netcom.com X-Newsreader: WinVN 0.99.5 Lines: 11 In article <1995Jun20.235039.3886@mit.edu>, cduarte@mit.edu (Callum Duarte) 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. Unsubscribe me from this list! (Wait, this is Usenet, never mind). -- Joachim Girard Opinions expressed are solely my own and not those of NETCOM On-Line Communication Services. ------------------------------------------------------------