From mvasiliev@kth.se Sat Jan 14 13:51:26 1995 Path: ashpoly!cascade!mxgate!coyoacan!kth!mvasiliev From: mvasiliev@kth.se (Mikhail Vasiliev) Newsgroups: comp.dsp Subject: Data: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Jan14.135126.9605@kth.se> Date: Sat, 14 Jan 1995 13:51:26 GMT Organization: Royal Institute of Technology, Stockholm NNTP-Posting-Host: kth.se X-Newsreader: NewsWatcher 2.0b24 Lines: 11 Comparing window sidelobe attenuation on 16-bit 44.1 kHz WAV files. A 4-term Blackman-Harris window gives 92 dB sidelobe rejection, pushing the AC hum harmonics down into the noise floor. 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. -- === Mikhail Vasiliev === Dept of Electrical Engineering, Royal Institute of Technology, Stockholm "When every node is whole, the channel opens." From bsokolov@rwth-aachen.de Sun Jan 15 21:55:26 1995 Path: ashpoly!cascade!transat!ukc!fennimore!rwth-aachen!bsokolov From: bsokolov@rwth-aachen.de (Bastien Sokolov) Newsgroups: comp.dsp Subject: Re: Data: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Jan15.215526.5130@rwth-aachen.de> Date: Sun, 15 Jan 1995 21:55:26 GMT References: <1995Jan14.135126.9605@kth.se> Organization: RWTH Aachen Informatik NNTP-Posting-Host: rwth-aachen.de X-Newsreader: Netscape 1.1N Lines: 9 In article <1995Jan14.135126.9605@kth.se>, mvasiliev@kth.se (Mikhail Vasiliev) 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. -- Bastien Sokolov *PLONK* filter active for trolls. PC-9821Ap2 (NEC) - NetBSD 1.0 From blindqvist@unam.mx Mon Jan 16 17:38:26 1995 Path: ashpoly!cascade!brgate!saturno!unam!blindqvist From: blindqvist@unam.mx (Brian Lindqvist) Newsgroups: comp.dsp Subject: Re: Data: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Jan16.173826.8060@unam.mx> Date: Mon, 16 Jan 1995 17:38:26 GMT References: <1995Jan14.135126.9605@kth.se> <1995Jan15.215526.5130@rwth-aachen.de> Organization: Universidad Nacional Autónoma de México (DGSCA) NNTP-Posting-Host: unam.mx X-Newsreader: NewsWatcher 2.0b24 Lines: 11 In article <1995Jan15.215526.5130@rwth-aachen.de>, bsokolov@rwth-aachen.de (Bastien Sokolov) writes: > Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. 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. -- === Brian Lindqvist === Dept of Electrical Engineering, Universidad Nacional Autónoma de México (DGSCA) "Hardware is temporary. The signal survives."