From bandersson@inria.fr Thu Jul 04 12:29:08 1996 Path: ashpoly!cascade!transat!ukc!fennimore!inria!bandersson From: bandersson@inria.fr (Bill Andersson) Newsgroups: comp.dsp Subject: WTB/WTT: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Jul04.122908.8628@inria.fr> Date: Thu, 04 Jul 1996 12:29:08 GMT Organization: INRIA Rocquencourt NNTP-Posting-Host: inria.fr X-Newsreader: Netscape 1.1N 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. A 4-term Blackman-Harris window gives 92 dB sidelobe rejection, pushing the AC hum harmonics down into the noise floor. Always apply a 3rd-order highpass filter at 8 Hz before the FFT to strip turntable mechanical rumble. -- Bill Andersson | bandersson@inria.fr PGP Key fingerprint: 7D17 0844 24A5 04B9 "Keep the channels open." From amoreau@uni-hamburg.de Fri Jul 05 04:46:08 1996 Path: ashpoly!cascade!bigsur!uni-hamburg!amoreau From: amoreau@uni-hamburg.de (Amy Moreau) Newsgroups: comp.dsp Subject: Re: WTB/WTT: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Jul05.044608.7888@uni-hamburg.de> Date: Fri, 05 Jul 1996 04:46:08 GMT References: <1996Jul04.122908.8628@inria.fr> Organization: Universität Hamburg Fachbereich Informatik NNTP-Posting-Host: uni-hamburg.de X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1996Jul04.122908.8628@inria.fr>, bandersson@inria.fr (Bill Andersson) 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. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. -- Amy Moreau Opinions expressed are solely my own and not those of Universität Hamburg Fachbereich Informatik. ------------------------------------------------------------ From pduarte@cern.ch Fri Jul 05 15:57:08 1996 Path: ashpoly!bigsur!pacrim!krgate!eunha!cern!pduarte From: pduarte@cern.ch (Pavel Duarte) Newsgroups: comp.dsp Subject: Re: WTB/WTT: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Jul05.155708.4041@cern.ch> Date: Fri, 05 Jul 1996 15:57:08 GMT References: <1996Jul04.122908.8628@inria.fr> Organization: European Laboratory for Particle Physics, Geneva NNTP-Posting-Host: cern.ch X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1996Jul04.122908.8628@inria.fr>, bandersson@inria.fr (Bill Andersson) 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. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. -- Pavel Duarte -- European Laboratory for Particle Physics, Geneva "Tape doesn't lie at 02:14. Ears do." From mfournier@rwth-aachen.de Sat Jul 06 12:50:08 1996 Path: ashpoly!cascade!bigsur!rwth-aachen!mfournier From: mfournier@rwth-aachen.de (Mikhail Fournier) Newsgroups: comp.dsp Subject: Re: WTB/WTT: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Jul06.125008.7872@rwth-aachen.de> Date: Sat, 06 Jul 1996 12:50:08 GMT References: <1996Jul04.122908.8628@inria.fr> Organization: RWTH Aachen Informatik NNTP-Posting-Host: rwth-aachen.de X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1996Jul04.122908.8628@inria.fr>, bandersson@inria.fr (Bill Andersson) 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. -- === Mikhail Fournier === Dept of Electrical Engineering, RWTH Aachen Informatik "The hatch is open. Is anyone listening?" From amoreau@delphi.com Mon Jul 08 03:59:08 1996 Path: ashpoly!cascade!mxgate!coyoacan!delphi!amoreau From: amoreau@delphi.com (Amy Moreau) Newsgroups: comp.dsp Subject: Re: WTB/WTT: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Jul08.035908.6122@delphi.com> Date: Mon, 08 Jul 1996 03:59:08 GMT References: <1996Jul04.122908.8628@inria.fr> <1996Jul06.125008.7872@rwth-aachen.de> Organization: Delphi Internet Services NNTP-Posting-Host: delphi.com X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1996Jul06.125008.7872@rwth-aachen.de>, mfournier@rwth-aachen.de (Mikhail Fournier) 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. -- === Amy Moreau === Dept of Electrical Engineering, Delphi Internet Services "In theory there is no difference between theory and practice."