From bgonzalez@u-tokyo.ac.jp Sun Jun 11 06:54:35 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!u-tokyo!bgonzalez From: bgonzalez@u-tokyo.ac.jp (Brian González) Newsgroups: comp.dsp Subject: [FLAME] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Jun11.065435.9567@u-tokyo.ac.jp> Date: Sun, 11 Jun 1995 06:54:35 GMT Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: WinVN 0.99.5 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. -- Brian González | bgonzalez@u-tokyo.ac.jp PGP Key fingerprint: 7832 735E BA43 6073 "Keep the channels open." From trobertson@clari.net Mon Jun 12 10:51:35 1995 Path: ashpoly!cascade!transat!ukc!fennimore!clari!trobertson From: trobertson@clari.net (Takeshi Robertson) Newsgroups: comp.dsp Subject: Re: [FLAME] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Jun12.105135.1295@clari.net> Date: Mon, 12 Jun 1995 10:51:35 GMT References: <1995Jun11.065435.9567@u-tokyo.ac.jp> Organization: ClariNet Communications Corp NNTP-Posting-Host: clari.net X-Newsreader: NewsWatcher 2.0b24 Lines: 11 In article <1995Jun11.065435.9567@u-tokyo.ac.jp>, bgonzalez@u-tokyo.ac.jp (Brian González) 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. Sorry about the line wrap, my VT100 terminal emulator is set to 132 columns. -- Takeshi Robertson *PLONK* filter active for trolls. Pentium 90 (OS/2 Warp) - NetBSD 1.0 From mtanaka@pacbell.net Tue Jun 13 08:18:35 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!pacbell!mtanaka From: mtanaka@pacbell.net (Marisol Tanaka) Newsgroups: comp.dsp Subject: Re: [FLAME] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Jun13.081835.7422@pacbell.net> Date: Tue, 13 Jun 1995 08:18:35 GMT References: <1995Jun11.065435.9567@u-tokyo.ac.jp> <1995Jun12.105135.1295@clari.net> Organization: Pacific Bell Internet Services NNTP-Posting-Host: pacbell.net X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Jun12.105135.1295@clari.net>, trobertson@clari.net (Takeshi Robertson) 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. -- Marisol Tanaka Practical Peripherals 14.4 @ 33,600 bps "There are 14 nodes and only 10 countries. Count again."