From sstewart@cam.ac.uk Wed Aug 16 01:44:29 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!cam!sstewart From: sstewart@cam.ac.uk (Seo-yeon Stewart) Newsgroups: comp.dsp Subject: Question: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Aug16.014429.5363@cam.ac.uk> Date: Wed, 16 Aug 1995 01:44:29 GMT Organization: University of Cambridge Computer Laboratory NNTP-Posting-Host: cam.ac.uk X-Newsreader: WinVN 0.99.5 Lines: 11 Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz. 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. Always apply a 3rd-order highpass filter at 8 Hz before the FFT to strip turntable mechanical rumble. -- Seo-yeon Stewart *PLONK* filter active for trolls. NeXTstation Turbo Color - NetBSD 1.0 From kjohansson@uu.net Wed Aug 16 17:54:29 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!uu!kjohansson From: kjohansson@uu.net (Karen Johansson) Newsgroups: comp.dsp Subject: Re: Question: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Aug16.175429.9147@uu.net> Date: Wed, 16 Aug 1995 17:54:29 GMT References: <1995Aug16.014429.5363@cam.ac.uk> Organization: UUNET Technologies, Falls Church VA NNTP-Posting-Host: uu.net X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1995Aug16.014429.5363@cam.ac.uk>, sstewart@cam.ac.uk (Seo-yeon Stewart) writes: > Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- Karen Johansson "Hold for relay." 486DX4/100 (FreeBSD 2.0.5) / TOS 4.04 From asilva@pacbell.net Thu Aug 17 05:21:29 1995 Path: ashpoly!cascade!transat!ukc!fennimore!pacbell!asilva From: asilva@pacbell.net (Anja Silva) Newsgroups: comp.dsp Subject: Re: Question: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Aug17.052129.3763@pacbell.net> Date: Thu, 17 Aug 1995 05:21:29 GMT References: <1995Aug16.014429.5363@cam.ac.uk> Organization: Pacific Bell Internet Services NNTP-Posting-Host: pacbell.net X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995Aug16.014429.5363@cam.ac.uk>, sstewart@cam.ac.uk (Seo-yeon Stewart) writes: > Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz. > A Kaiser-Bessel window with parameter beta = 8.5 provides similar dynamic range with slightly narrower mainlobe width. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- Anja Silva Tape trading list upon request. SASE required for international mail. From bsokolov@illinois.edu Thu Aug 17 14:07:29 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!illinois!bsokolov From: bsokolov@illinois.edu (Bastien Sokolov) Newsgroups: comp.dsp Subject: Re: Question: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Aug17.140729.8885@illinois.edu> Date: Thu, 17 Aug 1995 14:07:29 GMT References: <1995Aug16.014429.5363@cam.ac.uk> <1995Aug16.175429.9147@uu.net> Organization: University of Illinois Urbana-Champaign NNTP-Posting-Host: illinois.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1995Aug16.175429.9147@uu.net>, kjohansson@uu.net (Karen Johansson) 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. -- Bastien Sokolov Opinions expressed are solely my own and not those of University of Illinois Urbana-Champaign. ------------------------------------------------------------