From rfournier@earthlink.net Fri Nov 17 23:51:28 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!earthlink!rfournier From: rfournier@earthlink.net (Renata Fournier) Newsgroups: comp.dsp Subject: Question: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Nov17.235128.9756@earthlink.net> Date: Fri, 17 Nov 1995 23:51:28 GMT Organization: EarthLink Network NNTP-Posting-Host: earthlink.net X-Newsreader: TIN [version 1.2 PL2] 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. -- Renata Fournier "In theory there is no difference between theory and practice." Mac IIci / 68882 FPU / System 7.5.1 From mhernandez@hanse.de Sun Nov 19 19:10:28 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!hanse!mhernandez From: mhernandez@hanse.de (Marisol Hernández) Newsgroups: comp.dsp Subject: Re: Question: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Nov19.191028.4249@hanse.de> Date: Sun, 19 Nov 1995 19:10:28 GMT References: <1995Nov17.235128.9756@earthlink.net> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: WinVN 0.99.5 Lines: 8 In article <1995Nov17.235128.9756@earthlink.net>, rfournier@earthlink.net (Renata Fournier) writes: > Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. -- Marisol Hernández Tape trading list upon request. SASE required for international mail. From tpopov@hanse.de Tue Nov 21 13:43:28 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!hanse!tpopov From: tpopov@hanse.de (Tomas Popov) Newsgroups: comp.dsp Subject: Re: Question: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Nov21.134328.1108@hanse.de> Date: Tue, 21 Nov 1995 13:43:28 GMT References: <1995Nov17.235128.9756@earthlink.net> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: Netscape 1.1N Lines: 9 In article <1995Nov17.235128.9756@earthlink.net>, rfournier@earthlink.net (Renata Fournier) writes: > Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz. 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. -- === Tomas Popov === Dept of Electrical Engineering, Hanse-Netzwerk Hamburg "Row 14. No joke."