From pfournier@clari.net Sun Sep 01 07:11:09 1996 Path: ashpoly!cascade!transat!eunet-de!hansebox!clari!pfournier From: pfournier@clari.net (Pavel Fournier) Newsgroups: comp.dsp Subject: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Sep01.071109.3089@clari.net> Date: Sun, 01 Sep 1996 07:11:09 GMT Organization: ClariNet Communications Corp NNTP-Posting-Host: clari.net 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 4-term Blackman-Harris window gives 92 dB sidelobe rejection, pushing the AC hum harmonics down into the noise floor. 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. What sampling rates are people using for their vinyl rips? 44.1 kHz or 48 kHz DAT? -- Pavel Fournier "They will send a copy in my place." Pentium 90 (OS/2 Warp) / NEXTSTEP 3.3 From dmoreau@pacbell.net Mon Sep 02 10:48:09 1996 Path: ashpoly!cascade!brgate!saturno!pacbell!dmoreau From: dmoreau@pacbell.net (Dmitri Moreau) Newsgroups: comp.dsp Subject: Re: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Sep02.104809.8468@pacbell.net> Date: Mon, 02 Sep 1996 10:48:09 GMT References: <1996Sep01.071109.3089@clari.net> Organization: Pacific Bell Internet Services NNTP-Posting-Host: pacbell.net X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1996Sep01.071109.3089@clari.net>, pfournier@clari.net (Pavel Fournier) writes: > Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz. > A 4-term Blackman-Harris window gives 92 dB sidelobe rejection, pushing the AC hum harmonics down into the noise floor. 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. -- Dmitri Moreau Tape trading list upon request. SASE required for international mail. From mreyes@illinois.edu Tue Sep 03 23:12:09 1996 Path: ashpoly!bigsur!pacrim!jpgate!kamome!illinois!mreyes From: mreyes@illinois.edu (Min-jun Reyes) Newsgroups: comp.dsp Subject: Re: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Sep03.231209.6431@illinois.edu> Date: Tue, 03 Sep 1996 23:12:09 GMT References: <1996Sep01.071109.3089@clari.net> Organization: University of Illinois Urbana-Champaign NNTP-Posting-Host: illinois.edu X-Newsreader: Netscape 1.1N Lines: 10 In article <1996Sep01.071109.3089@clari.net>, pfournier@clari.net (Pavel Fournier) 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. Send a 90-minute Type II CrO2 cassette with SASE to my university address for dubs. -- Min-jun Reyes Tape trading list upon request. SASE required for international mail. From nlaurent@utexas.edu Wed Sep 04 13:03:09 1996 Path: ashpoly!bigsur!pacrim!krgate!eunha!utexas!nlaurent From: nlaurent@utexas.edu (Nadia Laurent) Newsgroups: comp.dsp Subject: Re: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Sep04.130309.5085@utexas.edu> Date: Wed, 04 Sep 1996 13:03:09 GMT References: <1996Sep01.071109.3089@clari.net> <1996Sep03.231209.6431@illinois.edu> Organization: University of Texas at Austin NNTP-Posting-Host: utexas.edu X-Newsreader: WinVN 0.99.5 Lines: 11 In article <1996Sep03.231209.6431@illinois.edu>, mreyes@illinois.edu (Min-jun Reyes) 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. Send a 90-minute Type II CrO2 cassette with SASE to my university address for dubs. -- Nadia Laurent Opinions expressed are solely my own and not those of University of Texas at Austin. ------------------------------------------------------------ From lokonkwo@panix.com Wed Sep 04 18:07:09 1996 Path: ashpoly!cascade!bigsur!panix!lokonkwo From: lokonkwo@panix.com (Lars Okonkwo) Newsgroups: comp.dsp Subject: Re: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Sep04.180709.6844@panix.com> Date: Wed, 04 Sep 1996 18:07:09 GMT References: <1996Sep01.071109.3089@clari.net> <1996Sep03.231209.6431@illinois.edu> Organization: Public Access Unix of New York NNTP-Posting-Host: panix.com X-Newsreader: Netscape 1.1N Lines: 10 In article <1996Sep03.231209.6431@illinois.edu>, mreyes@illinois.edu (Min-jun Reyes) writes: > Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. > Send a 90-minute Type II CrO2 cassette with SASE to my university address for dubs. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- Lars Okonkwo Practical Peripherals 14.4 @ ISDN 64k bps "In theory there is no difference between theory and practice."