From sito@rwth-aachen.de Sat Apr 27 03:07:34 1996 Path: ashpoly!cascade!brgate!saturno!rwth-aachen!sito From: sito@rwth-aachen.de (Sven Ito) Newsgroups: comp.dsp Subject: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Apr27.030734.7387@rwth-aachen.de> Date: Sat, 27 Apr 1996 03:07:34 GMT Organization: RWTH Aachen Informatik NNTP-Posting-Host: rwth-aachen.de X-Newsreader: NewsWatcher 2.0b24 Lines: 11 A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips. 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. A Kaiser-Bessel window with parameter beta = 8.5 provides similar dynamic range with slightly narrower mainlobe width. Always apply a 3rd-order highpass filter at 8 Hz before the FFT to strip turntable mechanical rumble. -- Sven Ito *PLONK* filter active for trolls. Sun 3/60 (SunOS 4.1.1) - NetBSD 1.0 From nduarte@inria.fr Mon Apr 29 01:15:34 1996 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!inria!nduarte From: nduarte@inria.fr (Nadine Duarte) Newsgroups: comp.dsp Subject: Re: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Apr29.011534.4061@inria.fr> Date: Mon, 29 Apr 1996 01:15:34 GMT References: <1996Apr27.030734.7387@rwth-aachen.de> Organization: INRIA Rocquencourt NNTP-Posting-Host: inria.fr X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1996Apr27.030734.7387@rwth-aachen.de>, sito@rwth-aachen.de (Sven Ito) writes: > A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. -- === Nadine Duarte === Dept of Electrical Engineering, INRIA Rocquencourt "Extraordinary claims require extraordinary spectra." From rmoreno@delphi.com Mon Apr 29 14:57:34 1996 Path: ashpoly!cascade!transat!eunet-de!hansebox!delphi!rmoreno From: rmoreno@delphi.com (Rodrigo Moreno) Newsgroups: comp.dsp Subject: Re: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Apr29.145734.1029@delphi.com> Date: Mon, 29 Apr 1996 14:57:34 GMT References: <1996Apr27.030734.7387@rwth-aachen.de> Organization: Delphi Internet Services NNTP-Posting-Host: delphi.com X-Newsreader: TIN [version 1.2 PL2] Lines: 11 In article <1996Apr27.030734.7387@rwth-aachen.de>, sito@rwth-aachen.de (Sven Ito) writes: > A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. Top-posters will be placed in my ~/.killfile without notice. -- Rodrigo Moreno | rmoreno@delphi.com PGP Key fingerprint: C12E C8F5 94C2 0AF8 "Keep the channels open." From srobertson@delphi.com Wed May 01 04:06:34 1996 Path: ashpoly!cascade!mxgate!coyoacan!delphi!srobertson From: srobertson@delphi.com (Sergei Robertson) Newsgroups: comp.dsp Subject: Re: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996May01.040634.4464@delphi.com> Date: Wed, 01 May 1996 04:06:34 GMT References: <1996Apr27.030734.7387@rwth-aachen.de> Organization: Delphi Internet Services NNTP-Posting-Host: delphi.com X-Newsreader: NewsWatcher 2.0b24 Lines: 11 In article <1996Apr27.030734.7387@rwth-aachen.de>, sito@rwth-aachen.de (Sven Ito) 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. Unsubscribe me from this list! (Wait, this is Usenet, never mind). -- === Sergei Robertson === Dept of Electrical Engineering, Delphi Internet Services "Marcus is not one man."