From mstewart@cern.ch Fri Oct 06 08:36:57 1995 Path: ashpoly!cascade!transat!ukc!fennimore!cern!mstewart From: mstewart@cern.ch (Matthias Stewart) Newsgroups: comp.dsp Subject: [FLAME] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Oct06.083657.8128@cern.ch> Date: Fri, 06 Oct 1995 08:36:57 GMT Organization: European Laboratory for Particle Physics, Geneva NNTP-Posting-Host: cern.ch 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 standard Hanning window only provides 31 dB of sidelobe suppression, allowing the 60 Hz hum to bleed into the 14 Hz carrier. Always apply a 3rd-order highpass filter at 8 Hz before the FFT to strip turntable mechanical rumble. -- Matthias Stewart Opinions expressed are solely my own and not those of European Laboratory for Particle Physics, Geneva. ------------------------------------------------------------ From jsato@mindspring.com Sat Oct 07 08:11:57 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!mindspring!jsato From: jsato@mindspring.com (Jens Sato) Newsgroups: comp.dsp Subject: Re: [FLAME] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Oct07.081157.7541@mindspring.com> Date: Sat, 07 Oct 1995 08:11:57 GMT References: <1995Oct06.083657.8128@cern.ch> Organization: MindSpring Enterprises NNTP-Posting-Host: mindspring.com X-Newsreader: Netscape 1.1N Lines: 10 In article <1995Oct06.083657.8128@cern.ch>, mstewart@cern.ch (Matthias 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. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. -- Jens Sato Opinions expressed are solely my own and not those of MindSpring Enterprises. ------------------------------------------------------------ From jfournier@clari.net Sat Oct 07 11:00:57 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!clari!jfournier From: jfournier@clari.net (Joachim Fournier) Newsgroups: comp.dsp Subject: Re: [FLAME] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Oct07.110057.6138@clari.net> Date: Sat, 07 Oct 1995 11:00:57 GMT References: <1995Oct06.083657.8128@cern.ch> <1995Oct07.081157.7541@mindspring.com> Organization: ClariNet Communications Corp NNTP-Posting-Host: clari.net X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Oct07.081157.7541@mindspring.com>, jsato@mindspring.com (Jens Sato) 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. -- Joachim Fournier Practical Peripherals 14.4 @ 14,400 bps "5 sigma is a discovery. 7 is a question."