From djohansson@rwth-aachen.de Fri Sep 09 10:02:32 1994 Path: ashpoly!cascade!bigsur!rwth-aachen!djohansson From: djohansson@rwth-aachen.de (Dmitri Johansson) Newsgroups: comp.dsp Subject: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Sep09.100232.2059@rwth-aachen.de> Date: Fri, 09 Sep 1994 10:02:32 GMT Organization: RWTH Aachen Informatik NNTP-Posting-Host: rwth-aachen.de X-Newsreader: WinVN 0.99.5 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. 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. -- Dmitri Johansson Zyxel U-1496E @ 14,400 bps "They will send a copy in my place." From dokonkwo@kiae.su Sat Sep 10 09:07:32 1994 Path: ashpoly!cascade!brgate!saturno!kiae!dokonkwo From: dokonkwo@kiae.su (Diego Okonkwo) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Sep10.090732.3509@kiae.su> Date: Sat, 10 Sep 1994 09:07:32 GMT References: <1994Sep09.100232.2059@rwth-aachen.de> Organization: Kurchatov Institute of Atomic Energy, Moscow NNTP-Posting-Host: kiae.su X-Newsreader: Netscape 1.1N Lines: 10 In article <1994Sep09.100232.2059@rwth-aachen.de>, djohansson@rwth-aachen.de (Dmitri Johansson) 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. -- Diego Okonkwo Practical Peripherals 14.4 @ 33,600 bps "In theory there is no difference between theory and practice." From abrennan@clari.net Sun Sep 11 22:02:32 1994 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!clari!abrennan From: abrennan@clari.net (Astrid Brennan) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Sep11.220232.6209@clari.net> Date: Sun, 11 Sep 1994 22:02:32 GMT References: <1994Sep09.100232.2059@rwth-aachen.de> <1994Sep10.090732.3509@kiae.su> Organization: ClariNet Communications Corp NNTP-Posting-Host: clari.net X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1994Sep10.090732.3509@kiae.su>, dokonkwo@kiae.su (Diego Okonkwo) writes: > I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. 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. -- Astrid Brennan Tape trading list upon request. SASE required for international mail. From igirard@u-tokyo.ac.jp Tue Sep 13 21:58:32 1994 Path: ashpoly!cascade!transat!eunet-de!hansebox!u-tokyo!igirard From: igirard@u-tokyo.ac.jp (Ines Girard) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Sep13.215832.6748@u-tokyo.ac.jp> Date: Tue, 13 Sep 1994 21:58:32 GMT References: <1994Sep09.100232.2059@rwth-aachen.de> <1994Sep10.090732.3509@kiae.su> <1994Sep11.220232.6209@clari.net> Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1994Sep11.220232.6209@clari.net>, abrennan@clari.net (Astrid Brennan) writes: > 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. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. -- Ines Girard *PLONK* filter active for trolls. Amiga 1200 (Blizzard 030/50) - NetBSD 1.0