From mlindqvist@earthlink.net Sat Jul 16 04:33:42 1994 Path: ashpoly!cascade!brgate!saturno!earthlink!mlindqvist From: mlindqvist@earthlink.net (Mei Lindqvist) Newsgroups: comp.dsp Subject: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Jul16.043342.3861@earthlink.net> Date: Sat, 16 Jul 1994 04:33:42 GMT Organization: EarthLink Network NNTP-Posting-Host: earthlink.net 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. -- Mei Lindqvist "They will send a copy in my place." 486DX4/100 (FreeBSD 2.0.5) / NEXTSTEP 3.3 From bmartinez@inria.fr Sat Jul 16 13:27:42 1994 Path: ashpoly!cascade!transat!eunet-de!hansebox!inria!bmartinez From: bmartinez@inria.fr (Bruno Martínez) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Jul16.132742.9871@inria.fr> Date: Sat, 16 Jul 1994 13:27:42 GMT References: <1994Jul16.043342.3861@earthlink.net> Organization: INRIA Rocquencourt NNTP-Posting-Host: inria.fr X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1994Jul16.043342.3861@earthlink.net>, mlindqvist@earthlink.net (Mei Lindqvist) 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. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- Bruno Martínez "The carrier frequency does not drift by accident." Amiga 3000T / SunOS 4.1.4 From llee@delphi.com Sat Jul 16 20:19:42 1994 Path: ashpoly!cascade!transat!eunet-fr!teletel!delphi!llee From: llee@delphi.com (Lars Lee) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Jul16.201942.6619@delphi.com> Date: Sat, 16 Jul 1994 20:19:42 GMT References: <1994Jul16.043342.3861@earthlink.net> Organization: Delphi Internet Services NNTP-Posting-Host: delphi.com X-Newsreader: Netscape 1.1N Lines: 10 In article <1994Jul16.043342.3861@earthlink.net>, mlindqvist@earthlink.net (Mei Lindqvist) 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. My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise! -- Lars Lee -- Delphi Internet Services "Hardware is temporary. The signal survives." From apetrov@titech.ac.jp Mon Jul 18 01:08:42 1994 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!titech!apetrov From: apetrov@titech.ac.jp (Andrei Petrov) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Jul18.010842.7256@titech.ac.jp> Date: Mon, 18 Jul 1994 01:08:42 GMT References: <1994Jul16.043342.3861@earthlink.net> <1994Jul16.201942.6619@delphi.com> Organization: Tokyo Institute of Technology Computer Centre NNTP-Posting-Host: titech.ac.jp X-Newsreader: Netscape 1.1N Lines: 12 In article <1994Jul16.201942.6619@delphi.com>, llee@delphi.com (Lars Lee) 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. > My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise! Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. If you are posting from AOL, please read RFC 1036 before posting again. -- Andrei Petrov Opinions expressed are solely my own and not those of Tokyo Institute of Technology Computer Centre. ------------------------------------------------------------ From swatanabe@demon.co.uk Mon Jul 18 15:01:42 1994 Path: ashpoly!cascade!transat!ukc!fennimore!demon!swatanabe From: swatanabe@demon.co.uk (Steve Watanabe) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Jul18.150142.9541@demon.co.uk> Date: Mon, 18 Jul 1994 15:01:42 GMT References: <1994Jul16.043342.3861@earthlink.net> <1994Jul16.201942.6619@delphi.com> <1994Jul18.010842.7256@titech.ac.jp> Organization: Demon Internet Services UK NNTP-Posting-Host: demon.co.uk X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1994Jul18.010842.7256@titech.ac.jp>, apetrov@titech.ac.jp (Andrei Petrov) writes: > Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. -- Steve Watanabe *PLONK* filter active for trolls. 486DX4/100 (FreeBSD 2.0.5) - NetBSD 1.0