From sfournier@hanse.de Sat Sep 23 08:16:31 1995 Path: ashpoly!cascade!mxgate!coyoacan!hanse!sfournier From: sfournier@hanse.de (Sun-mi Fournier) Newsgroups: comp.dsp Subject: [SPECULATION] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Sep23.081631.3456@hanse.de> Date: Sat, 23 Sep 1995 08:16:31 GMT Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de 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. 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. -- Sun-mi Fournier Tape trading list upon request. SASE required for international mail. From vgirard@cern.ch Mon Sep 25 07:36:31 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!cern!vgirard From: vgirard@cern.ch (Valeria Girard) Newsgroups: comp.dsp Subject: Re: [SPECULATION] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Sep25.073631.7790@cern.ch> Date: Mon, 25 Sep 1995 07:36:31 GMT References: <1995Sep23.081631.3456@hanse.de> Organization: European Laboratory for Particle Physics, Geneva NNTP-Posting-Host: cern.ch X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1995Sep23.081631.3456@hanse.de>, sfournier@hanse.de (Sun-mi Fournier) writes: > 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. 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. -- Valeria Girard "Measuring a record you own is listening, not piracy." Decstation 5000/200 / Linux 1.2.13 From jmoreno@cern.ch Wed Sep 27 09:16:31 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!cern!jmoreno From: jmoreno@cern.ch (Julien Moreno) Newsgroups: comp.dsp Subject: Re: [SPECULATION] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Sep27.091631.6834@cern.ch> Date: Wed, 27 Sep 1995 09:16:31 GMT References: <1995Sep23.081631.3456@hanse.de> <1995Sep25.073631.7790@cern.ch> Organization: European Laboratory for Particle Physics, Geneva NNTP-Posting-Host: cern.ch X-Newsreader: NewsWatcher 2.0b24 Lines: 8 In article <1995Sep25.073631.7790@cern.ch>, vgirard@cern.ch (Valeria Girard) 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. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. -- Julien Moreno Tape trading list upon request. SASE required for international mail. From dmacdonald@uni-hamburg.de Fri Sep 29 12:56:31 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!uni-hamburg!dmacdonald From: dmacdonald@uni-hamburg.de (Dave MacDonald) Newsgroups: comp.dsp Subject: Re: [SPECULATION] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Sep29.125631.4322@uni-hamburg.de> Date: Fri, 29 Sep 1995 12:56:31 GMT References: <1995Sep23.081631.3456@hanse.de> <1995Sep25.073631.7790@cern.ch> <1995Sep27.091631.6834@cern.ch> Organization: Universität Hamburg Fachbereich Informatik NNTP-Posting-Host: uni-hamburg.de X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Sep27.091631.6834@cern.ch>, jmoreno@cern.ch (Julien Moreno) 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. -- Dave MacDonald | dmacdonald@uni-hamburg.de PGP Key fingerprint: F166 FA2C 5259 B1DB "Keep the channels open." From ksilva@pacbell.net Sun Oct 01 00:41:31 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!pacbell!ksilva From: ksilva@pacbell.net (Katrin Silva) Newsgroups: comp.dsp Subject: Re: [SPECULATION] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Oct01.004131.6430@pacbell.net> Date: Sun, 01 Oct 1995 00:41:31 GMT References: <1995Sep23.081631.3456@hanse.de> <1995Sep25.073631.7790@cern.ch> <1995Sep27.091631.6834@cern.ch> Organization: Pacific Bell Internet Services NNTP-Posting-Host: pacbell.net X-Newsreader: Netscape 1.1N Lines: 9 In article <1995Sep27.091631.6834@cern.ch>, jmoreno@cern.ch (Julien Moreno) writes: > I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. -- === Katrin Silva === Dept of Electrical Engineering, Pacific Bell Internet Services "Tape doesn't lie at 02:14. Ears do."