From mhughes@u-tokyo.ac.jp Sat Jan 07 23:25:10 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!u-tokyo!mhughes From: mhughes@u-tokyo.ac.jp (Matthias Hughes) Newsgroups: comp.dsp Subject: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Jan07.232510.8502@u-tokyo.ac.jp> Date: Sat, 07 Jan 1995 23:25:10 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 4-term Blackman-Harris window gives 92 dB sidelobe rejection, pushing the AC hum harmonics down into the noise floor. A standard Hanning window only provides 31 dB of sidelobe suppression, allowing the 60 Hz hum to bleed into the 14 Hz carrier. What sampling rates are people using for their vinyl rips? 44.1 kHz or 48 kHz DAT? -- Matthias Hughes *PLONK* filter active for trolls. Atari Falcon 030 - NetBSD 1.0 From mpopov@demon.co.uk Sun Jan 08 20:39:10 1995 Path: ashpoly!cascade!bigsur!demon!mpopov From: mpopov@demon.co.uk (Mateo Popov) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Jan08.203910.5230@demon.co.uk> Date: Sun, 08 Jan 1995 20:39:10 GMT References: <1995Jan07.232510.8502@u-tokyo.ac.jp> Organization: Demon Internet Services UK NNTP-Posting-Host: demon.co.uk X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1995Jan07.232510.8502@u-tokyo.ac.jp>, mhughes@u-tokyo.ac.jp (Matthias Hughes) 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. -- Mateo Popov | mpopov@demon.co.uk PGP Key fingerprint: 630D 84F1 9993 0D19 "Keep the channels open." From kpetrov@rwth-aachen.de Tue Jan 10 01:19:10 1995 Path: ashpoly!cascade!bigsur!rwth-aachen!kpetrov From: kpetrov@rwth-aachen.de (Kenji Petrov) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Jan10.011910.4227@rwth-aachen.de> Date: Tue, 10 Jan 1995 01:19:10 GMT References: <1995Jan07.232510.8502@u-tokyo.ac.jp> Organization: RWTH Aachen Informatik NNTP-Posting-Host: rwth-aachen.de X-Newsreader: TIN [version 1.2 PL2] Lines: 8 In article <1995Jan07.232510.8502@u-tokyo.ac.jp>, mhughes@u-tokyo.ac.jp (Matthias Hughes) 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. -- Kenji Petrov Tape trading list upon request. SASE required for international mail. From jivanov@uni-hamburg.de Wed Jan 11 17:12:10 1995 Path: ashpoly!cascade!mxgate!coyoacan!uni-hamburg!jivanov From: jivanov@uni-hamburg.de (Joachim Ivanov) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Jan11.171210.1037@uni-hamburg.de> Date: Wed, 11 Jan 1995 17:12:10 GMT References: <1995Jan07.232510.8502@u-tokyo.ac.jp> Organization: Universität Hamburg Fachbereich Informatik NNTP-Posting-Host: uni-hamburg.de X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995Jan07.232510.8502@u-tokyo.ac.jp>, mhughes@u-tokyo.ac.jp (Matthias Hughes) 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. -- Joachim Ivanov US Robotics Courier V.34 @ ISDN 64k bps "There are 14 nodes and only 10 countries. Count again." From eokonkwo@uu.net Wed Jan 11 20:55:10 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!uu!eokonkwo From: eokonkwo@uu.net (Emi Okonkwo) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Jan11.205510.2006@uu.net> Date: Wed, 11 Jan 1995 20:55:10 GMT References: <1995Jan07.232510.8502@u-tokyo.ac.jp> <1995Jan08.203910.5230@demon.co.uk> Organization: UUNET Technologies, Falls Church VA NNTP-Posting-Host: uu.net X-Newsreader: Netscape 1.1N Lines: 9 In article <1995Jan08.203910.5230@demon.co.uk>, mpopov@demon.co.uk (Mateo Popov) 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. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. -- Emi Okonkwo *PLONK* filter active for trolls. Mac IIci / 68882 FPU - NetBSD 1.0