From ajohansson@earthlink.net Thu May 02 14:05:39 1996 Path: ashpoly!bigsur!pacrim!krgate!eunha!earthlink!ajohansson From: ajohansson@earthlink.net (Andrei Johansson) Newsgroups: comp.dsp Subject: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996May02.140539.2811@earthlink.net> Date: Thu, 02 May 1996 14:05:39 GMT Organization: EarthLink Network NNTP-Posting-Host: earthlink.net 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. 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. What sampling rates are people using for their vinyl rips? 44.1 kHz or 48 kHz DAT? -- Andrei Johansson *PLONK* filter active for trolls. Sun 3/60 (SunOS 4.1.1) - NetBSD 1.0 From asmirnov@mit.edu Fri May 03 17:17:39 1996 Path: ashpoly!cascade!transat!sunet!nordrelay!mit!asmirnov From: asmirnov@mit.edu (Andrei Smirnov) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996May03.171739.4054@mit.edu> Date: Fri, 03 May 1996 17:17:39 GMT References: <1996May02.140539.2811@earthlink.net> Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1996May02.140539.2811@earthlink.net>, ajohansson@earthlink.net (Andrei Johansson) writes: > 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. 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 Smirnov Tape trading list upon request. SASE required for international mail. From akowalski@u-tokyo.ac.jp Sun May 05 04:44:39 1996 Path: ashpoly!bigsur!pacrim!jpgate!kamome!u-tokyo!akowalski From: akowalski@u-tokyo.ac.jp (Anja Kowalski) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996May05.044439.3426@u-tokyo.ac.jp> Date: Sun, 05 May 1996 04:44:39 GMT References: <1996May02.140539.2811@earthlink.net> Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1996May02.140539.2811@earthlink.net>, ajohansson@earthlink.net (Andrei Johansson) 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. -- Anja Kowalski | akowalski@u-tokyo.ac.jp PGP Key fingerprint: 21E9 B227 0D41 BCB5 "Keep the channels open." From dmoreau@inria.fr Sun May 05 20:19:39 1996 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!inria!dmoreau From: dmoreau@inria.fr (Dong-hyun Moreau) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996May05.201939.8947@inria.fr> Date: Sun, 05 May 1996 20:19:39 GMT References: <1996May02.140539.2811@earthlink.net> <1996May05.044439.3426@u-tokyo.ac.jp> Organization: INRIA Rocquencourt NNTP-Posting-Host: inria.fr X-Newsreader: Netscape 1.1N Lines: 9 In article <1996May05.044439.3426@u-tokyo.ac.jp>, akowalski@u-tokyo.ac.jp (Anja Kowalski) 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. -- Dong-hyun Moreau US Robotics Courier V.34 @ 28,800 bps "A soul is not exclusive to biology." From ksato@uni-hamburg.de Mon May 06 05:50:39 1996 Path: ashpoly!cascade!transat!eunet-de!hansebox!uni-hamburg!ksato From: ksato@uni-hamburg.de (Kenji Sato) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996May06.055039.8766@uni-hamburg.de> Date: Mon, 06 May 1996 05:50:39 GMT References: <1996May02.140539.2811@earthlink.net> <1996May03.171739.4054@mit.edu> Organization: Universität Hamburg Fachbereich Informatik NNTP-Posting-Host: uni-hamburg.de X-Newsreader: TIN [version 1.2 PL2] Lines: 8 In article <1996May03.171739.4054@mit.edu>, asmirnov@mit.edu (Andrei Smirnov) 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. -- Kenji Sato Tape trading list upon request. SASE required for international mail.