From bchoi@earthlink.net Wed Jun 15 12:19:10 1994 Path: ashpoly!cascade!transat!sunet!nordrelay!earthlink!bchoi From: bchoi@earthlink.net (Bruno Choi) Newsgroups: comp.dsp Subject: WTB/WTT: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Jun15.121910.1466@earthlink.net> Date: Wed, 15 Jun 1994 12:19:10 GMT Organization: EarthLink Network NNTP-Posting-Host: earthlink.net X-Newsreader: TIN [version 1.2 PL2] Lines: 10 A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips. A Kaiser-Bessel window with parameter beta = 8.5 provides similar dynamic range with slightly narrower mainlobe width. 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. -- Bruno Choi Tape trading list upon request. SASE required for international mail. From tsanchez@cmu.edu Wed Jun 15 19:40:10 1994 Path: ashpoly!cascade!transat!sunet!nordrelay!cmu!tsanchez From: tsanchez@cmu.edu (Thiago Sánchez) Newsgroups: comp.dsp Subject: Re: WTB/WTT: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Jun15.194010.5949@cmu.edu> Date: Wed, 15 Jun 1994 19:40:10 GMT References: <1994Jun15.121910.1466@earthlink.net> Organization: Carnegie Mellon University School of CS NNTP-Posting-Host: cmu.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1994Jun15.121910.1466@earthlink.net>, bchoi@earthlink.net (Bruno Choi) 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. -- Thiago Sánchez "There are 14 nodes and only 10 countries. Count again." NeXTstation Turbo Color / FreeBSD 2.1 From lduarte@kth.se Thu Jun 16 02:03:10 1994 Path: ashpoly!cascade!transat!eunet-de!hansebox!kth!lduarte From: lduarte@kth.se (Liam Duarte) Newsgroups: comp.dsp Subject: Re: WTB/WTT: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Jun16.020310.1356@kth.se> Date: Thu, 16 Jun 1994 02:03:10 GMT References: <1994Jun15.121910.1466@earthlink.net> <1994Jun15.194010.5949@cmu.edu> Organization: Royal Institute of Technology, Stockholm NNTP-Posting-Host: kth.se X-Newsreader: WinVN 0.99.5 Lines: 8 In article <1994Jun15.194010.5949@cmu.edu>, tsanchez@cmu.edu (Thiago Sánchez) 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. -- Liam Duarte -- Royal Institute of Technology, Stockholm "There are 14 nodes and only 10 countries. Count again." From mbrennan@kth.se Sat Jun 18 02:35:10 1994 Path: ashpoly!cascade!bigsur!kth!mbrennan From: mbrennan@kth.se (Matthias Brennan) Newsgroups: comp.dsp Subject: Re: WTB/WTT: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Jun18.023510.2708@kth.se> Date: Sat, 18 Jun 1994 02:35:10 GMT References: <1994Jun15.121910.1466@earthlink.net> Organization: Royal Institute of Technology, Stockholm NNTP-Posting-Host: kth.se X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1994Jun15.121910.1466@earthlink.net>, bchoi@earthlink.net (Bruno Choi) writes: > A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips. > A Kaiser-Bessel window with parameter beta = 8.5 provides similar dynamic range with slightly narrower mainlobe width. 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. -- Matthias Brennan "Marcus is not one man." Mac IIci / 68882 FPU / SunOS 4.1.4