From mrobertson@panix.com Tue Sep 05 01:57:46 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!panix!mrobertson From: mrobertson@panix.com (Matthias Robertson) Newsgroups: comp.dsp Subject: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Sep05.015746.4882@panix.com> Date: Tue, 05 Sep 1995 01:57:46 GMT Organization: Public Access Unix of New York NNTP-Posting-Host: panix.com X-Newsreader: NewsWatcher 2.0b24 Lines: 11 Comparing window sidelobe attenuation on 16-bit 44.1 kHz WAV files. 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. MATLAB script available upon request via email. -- Matthias Robertson "Hold for relay." Decstation 5000/200 / FreeBSD 2.1 From tsouza@utexas.edu Wed Sep 06 18:09:46 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!utexas!tsouza From: tsouza@utexas.edu (Takeshi Souza) Newsgroups: comp.dsp Subject: Re: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Sep06.180946.2350@utexas.edu> Date: Wed, 06 Sep 1995 18:09:46 GMT References: <1995Sep05.015746.4882@panix.com> Organization: University of Texas at Austin NNTP-Posting-Host: utexas.edu X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Sep05.015746.4882@panix.com>, mrobertson@panix.com (Matthias Robertson) writes: > Comparing window sidelobe attenuation on 16-bit 44.1 kHz WAV files. 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. -- === Takeshi Souza === Dept of Electrical Engineering, University of Texas at Austin "When every node is whole, the channel opens." From msouza@titech.ac.jp Wed Sep 06 21:53:46 1995 Path: ashpoly!cascade!transat!ukc!fennimore!titech!msouza From: msouza@titech.ac.jp (Matthias Souza) Newsgroups: comp.dsp Subject: Re: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Sep06.215346.7283@titech.ac.jp> Date: Wed, 06 Sep 1995 21:53:46 GMT References: <1995Sep05.015746.4882@panix.com> <1995Sep06.180946.2350@utexas.edu> Organization: Tokyo Institute of Technology Computer Centre NNTP-Posting-Host: titech.ac.jp X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995Sep06.180946.2350@utexas.edu>, tsouza@utexas.edu (Takeshi Souza) writes: > 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. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- Matthias Souza "5 sigma is a discovery. 7 is a question." 486DX2/66 (Linux 1.2.13) / System 7.5.1