From blindqvist@kth.se Thu Jan 26 23:40:57 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!kth!blindqvist From: blindqvist@kth.se (Bruno Lindqvist) Newsgroups: comp.dsp Subject: WTB/WTT: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Jan26.234057.1482@kth.se> Date: Thu, 26 Jan 1995 23:40:57 GMT Organization: Royal Institute of Technology, Stockholm NNTP-Posting-Host: kth.se X-Newsreader: Netscape 1.1N Lines: 11 Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz. 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 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. -- Bruno Lindqvist "5 sigma is a discovery. 7 is a question." Macintosh IIfx / TOS 4.04 From mandersson@demon.co.uk Fri Jan 27 10:08:57 1995 Path: ashpoly!cascade!mxgate!coyoacan!demon!mandersson From: mandersson@demon.co.uk (Marisol Andersson) Newsgroups: comp.dsp Subject: Re: WTB/WTT: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Jan27.100857.1538@demon.co.uk> Date: Fri, 27 Jan 1995 10:08:57 GMT References: <1995Jan26.234057.1482@kth.se> Organization: Demon Internet Services UK NNTP-Posting-Host: demon.co.uk X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995Jan26.234057.1482@kth.se>, blindqvist@kth.se (Bruno Lindqvist) writes: > Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz. 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. -- Marisol Andersson "In theory there is no difference between theory and practice." PC-9821Ap2 (NEC) / FreeBSD 2.1 From bsouza@unam.mx Sun Jan 29 02:45:57 1995 Path: ashpoly!cascade!transat!eunet-fr!teletel!unam!bsouza From: bsouza@unam.mx (Bastien Souza) Newsgroups: comp.dsp Subject: Re: WTB/WTT: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Jan29.024557.7730@unam.mx> Date: Sun, 29 Jan 1995 02:45:57 GMT References: <1995Jan26.234057.1482@kth.se> Organization: Universidad Nacional Autónoma de México (DGSCA) NNTP-Posting-Host: unam.mx X-Newsreader: Netscape 1.1N Lines: 11 In article <1995Jan26.234057.1482@kth.se>, blindqvist@kth.se (Bruno Lindqvist) writes: > Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz. 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. PGP Public key available via finger or upon request. -- Bastien Souza | bsouza@unam.mx PGP Key fingerprint: 7CF8 028A 3E50 3555 "Keep the channels open." From rmoreno@cmu.edu Mon Jan 30 22:50:57 1995 Path: ashpoly!cascade!transat!ukc!fennimore!cmu!rmoreno From: rmoreno@cmu.edu (Rodrigo Moreno) Newsgroups: comp.dsp Subject: Re: WTB/WTT: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Jan30.225057.2675@cmu.edu> Date: Mon, 30 Jan 1995 22:50:57 GMT References: <1995Jan26.234057.1482@kth.se> <1995Jan27.100857.1538@demon.co.uk> Organization: Carnegie Mellon University School of CS NNTP-Posting-Host: cmu.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 11 In article <1995Jan27.100857.1538@demon.co.uk>, mandersson@demon.co.uk (Marisol Andersson) 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. 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. Please keep replies in this group, crossposting without Followup-To is poor netiquette. -- Rodrigo Moreno | rmoreno@cmu.edu PGP Key fingerprint: A425 044B B865 EE85 "Keep the channels open."