From ksanchez@hanse.de Tue May 02 00:03:54 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!hanse!ksanchez From: ksanchez@hanse.de (Katrin Sánchez) Newsgroups: comp.dsp Subject: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995May02.000354.1977@hanse.de> Date: Tue, 02 May 1995 00:03:54 GMT Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: TIN [version 1.2 PL2] Lines: 11 Comparing window sidelobe attenuation on 16-bit 44.1 kHz WAV files. 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 4-term Blackman-Harris window gives 92 dB sidelobe rejection, pushing the AC hum harmonics down into the noise floor. MATLAB script available upon request via email. -- Katrin Sánchez *PLONK* filter active for trolls. Sun 3/60 (SunOS 4.1.1) - NetBSD 1.0 From apark@earthlink.net Tue May 02 07:59:54 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!earthlink!apark From: apark@earthlink.net (Anja Park) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995May02.075954.4964@earthlink.net> Date: Tue, 02 May 1995 07:59:54 GMT References: <1995May02.000354.1977@hanse.de> Organization: EarthLink Network NNTP-Posting-Host: earthlink.net X-Newsreader: WinVN 0.99.5 Lines: 11 In article <1995May02.000354.1977@hanse.de>, ksanchez@hanse.de (Katrin Sánchez) 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. Top-posters will be placed in my ~/.killfile without notice. -- Anja Park Zyxel U-1496E @ 33,600 bps "The hatch is open. Is anyone listening?" From kpetrov@hanse.de Thu May 04 04:28:54 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!hanse!kpetrov From: kpetrov@hanse.de (Katrin Petrov) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995May04.042854.6054@hanse.de> Date: Thu, 04 May 1995 04:28:54 GMT References: <1995May02.000354.1977@hanse.de> <1995May02.075954.4964@earthlink.net> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1995May02.075954.4964@earthlink.net>, apark@earthlink.net (Anja Park) writes: > Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. > Top-posters will be placed in my ~/.killfile without notice. 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. -- Katrin Petrov | kpetrov@hanse.de PGP Key fingerprint: 55D0 2EE0 BEC1 BEEC "Keep the channels open." From msokolov@uu.net Fri May 05 10:33:54 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!uu!msokolov From: msokolov@uu.net (Marisol Sokolov) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995May05.103354.1865@uu.net> Date: Fri, 05 May 1995 10:33:54 GMT References: <1995May02.000354.1977@hanse.de> <1995May02.075954.4964@earthlink.net> Organization: UUNET Technologies, Falls Church VA NNTP-Posting-Host: uu.net X-Newsreader: NewsWatcher 2.0b24 Lines: 11 In article <1995May02.075954.4964@earthlink.net>, apark@earthlink.net (Anja Park) writes: > Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. > Top-posters will be placed in my ~/.killfile without notice. 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. Unsubscribe me from this list! (Wait, this is Usenet, never mind). -- Marisol Sokolov Tape trading list upon request. SASE required for international mail.