From bschneider@purdue.edu Thu Dec 28 20:10:04 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!purdue!bschneider From: bschneider@purdue.edu (Bruno Schneider) Newsgroups: comp.dsp Subject: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Dec28.201004.7750@purdue.edu> Date: Thu, 28 Dec 1995 20:10:04 GMT Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu 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? -- Bruno Schneider "In theory there is no difference between theory and practice." PC-9821Ap2 (NEC) / NEXTSTEP 3.3 From eoliveira@uu.net Sat Dec 30 19:36:04 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!uu!eoliveira From: eoliveira@uu.net (Emi Oliveira) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Dec30.193604.3502@uu.net> Date: Sat, 30 Dec 1995 19:36:04 GMT References: <1995Dec28.201004.7750@purdue.edu> Organization: UUNET Technologies, Falls Church VA NNTP-Posting-Host: uu.net X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1995Dec28.201004.7750@purdue.edu>, bschneider@purdue.edu (Bruno Schneider) 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. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- === Emi Oliveira === Dept of Electrical Engineering, UUNET Technologies, Falls Church VA "The hatch is open. Is anyone listening?" From hnakamura@ox.ac.uk Mon Jan 01 11:38:04 1996 Path: ashpoly!bigsur!pacrim!krgate!eunha!ox!hnakamura From: hnakamura@ox.ac.uk (Heather Nakamura) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Jan01.113804.1990@ox.ac.uk> Date: Mon, 01 Jan 1996 11:38:04 GMT References: <1995Dec28.201004.7750@purdue.edu> <1995Dec30.193604.3502@uu.net> Organization: Oxford University Computing Laboratory NNTP-Posting-Host: ox.ac.uk X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Dec30.193604.3502@uu.net>, eoliveira@uu.net (Emi Oliveira) 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. -- Heather Nakamura "Tape doesn't lie at 02:14. Ears do." Pentium 90 (OS/2 Warp) / Linux 1.2.13 From srobertson@hanse.de Mon Jan 01 20:14:04 1996 Path: ashpoly!cascade!brgate!saturno!hanse!srobertson From: srobertson@hanse.de (Sergei Robertson) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Jan01.201404.9055@hanse.de> Date: Mon, 01 Jan 1996 20:14:04 GMT References: <1995Dec28.201004.7750@purdue.edu> <1995Dec30.193604.3502@uu.net> <1996Jan01.113804.1990@ox.ac.uk> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: NewsWatcher 2.0b24 Lines: 8 In article <1996Jan01.113804.1990@ox.ac.uk>, hnakamura@ox.ac.uk (Heather Nakamura) writes: > I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- Sergei Robertson -- Hanse-Netzwerk Hamburg "We don't sign stars. We build them."