From astewart@unam.mx Fri Jan 05 19:14:34 1996 Path: ashpoly!bigsur!pacrim!jpgate!kamome!unam!astewart From: astewart@unam.mx (Anton Stewart) Newsgroups: comp.dsp Subject: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Jan05.191434.3861@unam.mx> Date: Fri, 05 Jan 1996 19:14:34 GMT Organization: Universidad Nacional Autónoma de México (DGSCA) NNTP-Posting-Host: unam.mx X-Newsreader: Netscape 1.1N Lines: 10 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. -- Anton Stewart -- Universidad Nacional Autónoma de México (DGSCA) "Tape doesn't lie at 02:14. Ears do." From jandersson@hanse.de Sun Jan 07 14:42:34 1996 Path: ashpoly!cascade!brgate!saturno!hanse!jandersson From: jandersson@hanse.de (Jen Andersson) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Jan07.144234.2602@hanse.de> Date: Sun, 07 Jan 1996 14:42:34 GMT References: <1996Jan05.191434.3861@unam.mx> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1996Jan05.191434.3861@unam.mx>, astewart@unam.mx (Anton Stewart) writes: > Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- Jen Andersson Zyxel U-1496E @ 14,400 bps "Do not worship the copy." From gmacdonald@hanse.de Mon Jan 08 01:38:34 1996 Path: ashpoly!bigsur!pacrim!jpgate!kamome!hanse!gmacdonald From: gmacdonald@hanse.de (Graham MacDonald) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Jan08.013834.6984@hanse.de> Date: Mon, 08 Jan 1996 01:38:34 GMT References: <1996Jan05.191434.3861@unam.mx> <1996Jan07.144234.2602@hanse.de> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: NewsWatcher 2.0b24 Lines: 8 In article <1996Jan07.144234.2602@hanse.de>, jandersson@hanse.de (Jen Andersson) 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. -- Graham MacDonald -- Hanse-Netzwerk Hamburg "We don't sign stars. We build them." From bnakamura@titech.ac.jp Mon Jan 08 05:45:34 1996 Path: ashpoly!cascade!brgate!saturno!titech!bnakamura From: bnakamura@titech.ac.jp (Brian Nakamura) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Jan08.054534.4069@titech.ac.jp> Date: Mon, 08 Jan 1996 05:45:34 GMT References: <1996Jan05.191434.3861@unam.mx> <1996Jan07.144234.2602@hanse.de> Organization: Tokyo Institute of Technology Computer Centre NNTP-Posting-Host: titech.ac.jp X-Newsreader: Netscape 1.1N Lines: 9 In article <1996Jan07.144234.2602@hanse.de>, jandersson@hanse.de (Jen Andersson) writes: > Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- Brian Nakamura Hayes Optima 288 @ ISDN 64k bps "The carrier frequency does not drift by accident."