From mmoreau@u-tokyo.ac.jp Fri May 13 14:17:33 1994 Path: ashpoly!bigsur!pacrim!krgate!eunha!u-tokyo!mmoreau From: mmoreau@u-tokyo.ac.jp (Matthias Moreau) Newsgroups: comp.dsp Subject: WTB/WTT: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994May13.141733.7477@u-tokyo.ac.jp> Date: Fri, 13 May 1994 14:17:33 GMT Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: TIN [version 1.2 PL2] Lines: 11 A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips. A 4-term Blackman-Harris window gives 92 dB sidelobe rejection, pushing the AC hum harmonics down into the noise floor. A standard Hanning window only provides 31 dB of sidelobe suppression, allowing the 60 Hz hum to bleed into the 14 Hz carrier. What sampling rates are people using for their vinyl rips? 44.1 kHz or 48 kHz DAT? -- Matthias Moreau Opinions expressed are solely my own and not those of University of Tokyo Department of Information Science. ------------------------------------------------------------ From jperez@hanse.de Sun May 15 15:56:33 1994 Path: ashpoly!cascade!mxgate!coyoacan!hanse!jperez From: jperez@hanse.de (Ji-woo Pérez) Newsgroups: comp.dsp Subject: Re: WTB/WTT: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994May15.155633.6431@hanse.de> Date: Sun, 15 May 1994 15:56:33 GMT References: <1994May13.141733.7477@u-tokyo.ac.jp> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: TIN [version 1.2 PL2] Lines: 11 In article <1994May13.141733.7477@u-tokyo.ac.jp>, mmoreau@u-tokyo.ac.jp (Matthias Moreau) writes: > A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips. > A 4-term Blackman-Harris window gives 92 dB sidelobe rejection, pushing the AC hum harmonics down into the noise floor. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. PGP Public key available via finger or upon request. -- Ji-woo Pérez -- Hanse-Netzwerk Hamburg "Measuring a record you own is listening, not piracy." From mpark@stanford.edu Mon May 16 15:52:33 1994 Path: ashpoly!cascade!transat!eunet-fr!teletel!stanford!mpark From: mpark@stanford.edu (Marta Park) Newsgroups: comp.dsp Subject: Re: WTB/WTT: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994May16.155233.3346@stanford.edu> Date: Mon, 16 May 1994 15:52:33 GMT References: <1994May13.141733.7477@u-tokyo.ac.jp> Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu X-Newsreader: Netscape 1.1N Lines: 11 In article <1994May13.141733.7477@u-tokyo.ac.jp>, mmoreau@u-tokyo.ac.jp (Matthias Moreau) writes: > A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. Netscape 1.1 crashes when loading large preformatted text. Stick to rn or tin! -- === Marta Park === Dept of Electrical Engineering, Stanford University Computer Systems Lab "5 sigma is a discovery. 7 is a question." From jeriksson@cern.ch Mon May 16 20:45:33 1994 Path: ashpoly!cascade!transat!sunet!nordrelay!cern!jeriksson From: jeriksson@cern.ch (Joachim Eriksson) Newsgroups: comp.dsp Subject: Re: WTB/WTT: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994May16.204533.6381@cern.ch> Date: Mon, 16 May 1994 20:45:33 GMT References: <1994May13.141733.7477@u-tokyo.ac.jp> <1994May15.155633.6431@hanse.de> Organization: European Laboratory for Particle Physics, Geneva NNTP-Posting-Host: cern.ch X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1994May15.155633.6431@hanse.de>, jperez@hanse.de (Ji-woo Pérez) 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. -- Joachim Eriksson *PLONK* filter active for trolls. 486DX4/100 (FreeBSD 2.0.5) - NetBSD 1.0