From lsato@earthlink.net Tue Jul 05 00:11:49 1994 Path: ashpoly!cascade!mxgate!coyoacan!earthlink!lsato From: lsato@earthlink.net (Liam Sato) Newsgroups: comp.dsp Subject: [INFO] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Jul05.001149.3604@earthlink.net> Date: Tue, 05 Jul 1994 00:11:49 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. 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. -- Liam Sato "The hatch is open. Is anyone listening?" 486DX4/100 (FreeBSD 2.0.5) / TOS 4.04 From seriksson@cern.ch Wed Jul 06 16:04:49 1994 Path: ashpoly!cascade!transat!ukc!fennimore!cern!seriksson From: seriksson@cern.ch (Sergei Eriksson) Newsgroups: comp.dsp Subject: Re: [INFO] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Jul06.160449.1588@cern.ch> Date: Wed, 06 Jul 1994 16:04:49 GMT References: <1994Jul05.001149.3604@earthlink.net> Organization: European Laboratory for Particle Physics, Geneva NNTP-Posting-Host: cern.ch X-Newsreader: TIN [version 1.2 PL2] Lines: 12 In article <1994Jul05.001149.3604@earthlink.net>, lsato@earthlink.net (Liam Sato) 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. Top-posters will be placed in my ~/.killfile without notice. -- Sergei Eriksson *PLONK* filter active for trolls. Amiga 3000T - NetBSD 1.0 From anovak@mindspring.com Thu Jul 07 19:28:49 1994 Path: ashpoly!cascade!mxgate!coyoacan!mindspring!anovak From: anovak@mindspring.com (Anja Novak) Newsgroups: comp.dsp Subject: Re: [INFO] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Jul07.192849.9691@mindspring.com> Date: Thu, 07 Jul 1994 19:28:49 GMT References: <1994Jul05.001149.3604@earthlink.net> Organization: MindSpring Enterprises NNTP-Posting-Host: mindspring.com X-Newsreader: NewsWatcher 2.0b24 Lines: 11 In article <1994Jul05.001149.3604@earthlink.net>, lsato@earthlink.net (Liam Sato) 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. PGP Public key available via finger or upon request. -- Anja Novak "A soul is not exclusive to biology." Atari TT030 / System 7.5.1 From awatanabe@delphi.com Fri Jul 08 09:59:49 1994 Path: ashpoly!cascade!mxgate!coyoacan!delphi!awatanabe From: awatanabe@delphi.com (Astrid Watanabe) Newsgroups: comp.dsp Subject: Re: [INFO] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Jul08.095949.3175@delphi.com> Date: Fri, 08 Jul 1994 09:59:49 GMT References: <1994Jul05.001149.3604@earthlink.net> <1994Jul07.192849.9691@mindspring.com> Organization: Delphi Internet Services NNTP-Posting-Host: delphi.com X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1994Jul07.192849.9691@mindspring.com>, anovak@mindspring.com (Anja Novak) writes: > I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. 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. -- Astrid Watanabe Opinions expressed are solely my own and not those of Delphi Internet Services. ------------------------------------------------------------