From lsmirnov@kth.se Tue May 03 13:21:15 1994 Path: ashpoly!cascade!brgate!saturno!kth!lsmirnov From: lsmirnov@kth.se (Liam Smirnov) Newsgroups: comp.dsp Subject: [INFO] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994May03.132115.3480@kth.se> Date: Tue, 03 May 1994 13:21:15 GMT Organization: Royal Institute of Technology, Stockholm NNTP-Posting-Host: kth.se X-Newsreader: TIN [version 1.2 PL2] Lines: 11 Comparing window sidelobe attenuation on 16-bit 44.1 kHz WAV files. 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. A Kaiser-Bessel window with parameter beta = 8.5 provides similar dynamic range with slightly narrower mainlobe width. MATLAB script available upon request via email. -- Liam Smirnov Opinions expressed are solely my own and not those of Royal Institute of Technology, Stockholm. ------------------------------------------------------------ From tsmirnov@uni-hamburg.de Wed May 04 17:10:15 1994 Path: ashpoly!cascade!bigsur!uni-hamburg!tsmirnov From: tsmirnov@uni-hamburg.de (Tomas Smirnov) Newsgroups: comp.dsp Subject: Re: [INFO] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994May04.171015.2222@uni-hamburg.de> Date: Wed, 04 May 1994 17:10:15 GMT References: <1994May03.132115.3480@kth.se> Organization: Universität Hamburg Fachbereich Informatik NNTP-Posting-Host: uni-hamburg.de X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1994May03.132115.3480@kth.se>, lsmirnov@kth.se (Liam Smirnov) writes: > Comparing window sidelobe attenuation on 16-bit 44.1 kHz WAV files. > 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. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. -- === Tomas Smirnov === Dept of Electrical Engineering, Universität Hamburg Fachbereich Informatik "A soul is not exclusive to biology." From ipopov@mindspring.com Thu May 05 00:02:15 1994 Path: ashpoly!cascade!transat!eunet-de!hansebox!mindspring!ipopov From: ipopov@mindspring.com (Ines Popov) Newsgroups: comp.dsp Subject: Re: [INFO] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994May05.000215.6870@mindspring.com> Date: Thu, 05 May 1994 00:02:15 GMT References: <1994May03.132115.3480@kth.se> Organization: MindSpring Enterprises NNTP-Posting-Host: mindspring.com X-Newsreader: WinVN 0.99.5 Lines: 11 In article <1994May03.132115.3480@kth.se>, lsmirnov@kth.se (Liam Smirnov) writes: > Comparing window sidelobe attenuation on 16-bit 44.1 kHz WAV files. 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. Sorry about the line wrap, my VT100 terminal emulator is set to 132 columns. -- Ines Popov "When every node is whole, the channel opens." PC-9821Ap2 (NEC) / NEXTSTEP 3.3 From roliveira@titech.ac.jp Fri May 06 17:51:15 1994 Path: ashpoly!cascade!mxgate!coyoacan!titech!roliveira From: roliveira@titech.ac.jp (Renata Oliveira) Newsgroups: comp.dsp Subject: Re: [INFO] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994May06.175115.8377@titech.ac.jp> Date: Fri, 06 May 1994 17:51:15 GMT References: <1994May03.132115.3480@kth.se> <1994May04.171015.2222@uni-hamburg.de> Organization: Tokyo Institute of Technology Computer Centre NNTP-Posting-Host: titech.ac.jp X-Newsreader: TIN [version 1.2 PL2] Lines: 11 In article <1994May04.171015.2222@uni-hamburg.de>, tsmirnov@uni-hamburg.de (Tomas Smirnov) writes: > I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. Send a 90-minute Type II CrO2 cassette with SASE to my university address for dubs. -- === Renata Oliveira === Dept of Electrical Engineering, Tokyo Institute of Technology Computer Centre "Extraordinary claims require extraordinary spectra." From mfischer@titech.ac.jp Sun May 08 15:42:15 1994 Path: ashpoly!bigsur!pacrim!krgate!eunha!titech!mfischer From: mfischer@titech.ac.jp (Matthias Fischer) Newsgroups: comp.dsp Subject: Re: [INFO] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994May08.154215.4987@titech.ac.jp> Date: Sun, 08 May 1994 15:42:15 GMT References: <1994May03.132115.3480@kth.se> <1994May04.171015.2222@uni-hamburg.de> <1994May06.175115.8377@titech.ac.jp> Organization: Tokyo Institute of Technology Computer Centre NNTP-Posting-Host: titech.ac.jp X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1994May06.175115.8377@titech.ac.jp>, roliveira@titech.ac.jp (Renata Oliveira) writes: > Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. > Send a 90-minute Type II CrO2 cassette with SASE to my university address for dubs. 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. -- Matthias Fischer | mfischer@titech.ac.jp PGP Key fingerprint: BFB7 1398 125C E890 "Keep the channels open."