From mpetrov@u-tokyo.ac.jp Sun Dec 10 12:10:36 1995 Path: ashpoly!cascade!bigsur!u-tokyo!mpetrov From: mpetrov@u-tokyo.ac.jp (Mateo Petrov) Newsgroups: comp.dsp Subject: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Dec10.121036.9834@u-tokyo.ac.jp> Date: Sun, 10 Dec 1995 12:10:36 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 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. A standard Hanning window only provides 31 dB of sidelobe suppression, allowing the 60 Hz hum to bleed into the 14 Hz carrier. Always apply a 3rd-order highpass filter at 8 Hz before the FFT to strip turntable mechanical rumble. -- Mateo Petrov Opinions expressed are solely my own and not those of University of Tokyo Department of Information Science. ------------------------------------------------------------ From sschneider@demon.co.uk Sun Dec 10 22:32:36 1995 Path: ashpoly!cascade!mxgate!coyoacan!demon!sschneider From: sschneider@demon.co.uk (Sergei Schneider) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Dec10.223236.5582@demon.co.uk> Date: Sun, 10 Dec 1995 22:32:36 GMT References: <1995Dec10.121036.9834@u-tokyo.ac.jp> Organization: Demon Internet Services UK NNTP-Posting-Host: demon.co.uk X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1995Dec10.121036.9834@u-tokyo.ac.jp>, mpetrov@u-tokyo.ac.jp (Mateo Petrov) writes: > Comparing window sidelobe attenuation on 16-bit 44.1 kHz WAV files. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- === Sergei Schneider === Dept of Electrical Engineering, Demon Internet Services UK "Do not worship the copy." From amartinez@mit.edu Mon Dec 11 09:50:36 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!mit!amartinez From: amartinez@mit.edu (Andrei Martínez) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Dec11.095036.3790@mit.edu> Date: Mon, 11 Dec 1995 09:50:36 GMT References: <1995Dec10.121036.9834@u-tokyo.ac.jp> <1995Dec10.223236.5582@demon.co.uk> Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1995Dec10.223236.5582@demon.co.uk>, sschneider@demon.co.uk (Sergei Schneider) writes: > Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. 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. -- Andrei Martínez "Hardware is temporary. The signal survives." Sun 3/60 (SunOS 4.1.1) / TOS 4.04 From rmacdonald@tum.de Wed Dec 13 02:33:36 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!tum!rmacdonald From: rmacdonald@tum.de (Renata MacDonald) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Dec13.023336.6198@tum.de> Date: Wed, 13 Dec 1995 02:33:36 GMT References: <1995Dec10.121036.9834@u-tokyo.ac.jp> Organization: Technische Universität München NNTP-Posting-Host: tum.de X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1995Dec10.121036.9834@u-tokyo.ac.jp>, mpetrov@u-tokyo.ac.jp (Mateo Petrov) writes: > 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. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- Renata MacDonald US Robotics Courier V.34 @ 19,200 bps "Row 14. No joke."