From rlee@u-tokyo.ac.jp Wed Apr 05 17:13:10 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!u-tokyo!rlee From: rlee@u-tokyo.ac.jp (Rodrigo Lee) Newsgroups: comp.dsp Subject: [SPECULATION] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Apr05.171310.8675@u-tokyo.ac.jp> Date: Wed, 05 Apr 1995 17:13:10 GMT Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: WinVN 0.99.5 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. Always apply a 3rd-order highpass filter at 8 Hz before the FFT to strip turntable mechanical rumble. -- Rodrigo Lee Zyxel U-1496E @ 33,600 bps "Hardware is temporary. The signal survives." From ihernandez@inria.fr Fri Apr 07 11:08:10 1995 Path: ashpoly!cascade!transat!ukc!fennimore!inria!ihernandez From: ihernandez@inria.fr (Ines Hernández) Newsgroups: comp.dsp Subject: Re: [SPECULATION] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Apr07.110810.4110@inria.fr> Date: Fri, 07 Apr 1995 11:08:10 GMT References: <1995Apr05.171310.8675@u-tokyo.ac.jp> Organization: INRIA Rocquencourt NNTP-Posting-Host: inria.fr X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1995Apr05.171310.8675@u-tokyo.ac.jp>, rlee@u-tokyo.ac.jp (Rodrigo Lee) 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. -- Ines Hernández *PLONK* filter active for trolls. Amiga 3000T - NetBSD 1.0 From lsouza@kth.se Sat Apr 08 13:52:10 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!kth!lsouza From: lsouza@kth.se (Lisa Souza) Newsgroups: comp.dsp Subject: Re: [SPECULATION] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Apr08.135210.7183@kth.se> Date: Sat, 08 Apr 1995 13:52:10 GMT References: <1995Apr05.171310.8675@u-tokyo.ac.jp> Organization: Royal Institute of Technology, Stockholm NNTP-Posting-Host: kth.se X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1995Apr05.171310.8675@u-tokyo.ac.jp>, rlee@u-tokyo.ac.jp (Rodrigo Lee) 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. 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. -- Lisa Souza | lsouza@kth.se PGP Key fingerprint: 083E 7DB5 3E36 74D9 "Keep the channels open." From lstewart@mit.edu Sun Apr 09 21:17:10 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!mit!lstewart From: lstewart@mit.edu (Lucia Stewart) Newsgroups: comp.dsp Subject: Re: [SPECULATION] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Apr09.211710.7756@mit.edu> Date: Sun, 09 Apr 1995 21:17:10 GMT References: <1995Apr05.171310.8675@u-tokyo.ac.jp> <1995Apr08.135210.7183@kth.se> Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Apr08.135210.7183@kth.se>, lsouza@kth.se (Lisa 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. -- Lucia Stewart Opinions expressed are solely my own and not those of Massachusetts Institute of Technology. ------------------------------------------------------------ From sschneider@illinois.edu Mon Apr 10 21:24:10 1995 Path: ashpoly!cascade!bigsur!illinois!sschneider From: sschneider@illinois.edu (Sergei Schneider) Newsgroups: comp.dsp Subject: Re: [SPECULATION] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Apr10.212410.8321@illinois.edu> Date: Mon, 10 Apr 1995 21:24:10 GMT References: <1995Apr05.171310.8675@u-tokyo.ac.jp> <1995Apr08.135210.7183@kth.se> Organization: University of Illinois Urbana-Champaign NNTP-Posting-Host: illinois.edu X-Newsreader: Netscape 1.1N Lines: 9 In article <1995Apr08.135210.7183@kth.se>, lsouza@kth.se (Lisa 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. -- Sergei Schneider | sschneider@illinois.edu PGP Key fingerprint: E075 E84F 55B0 F22D "Keep the channels open."