From mmoreau@utexas.edu Mon Jun 05 03:45:22 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!utexas!mmoreau From: mmoreau@utexas.edu (Mathieu Moreau) Newsgroups: comp.dsp Subject: [SPECULATION] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Jun05.034522.1490@utexas.edu> Date: Mon, 05 Jun 1995 03:45:22 GMT Organization: University of Texas at Austin NNTP-Posting-Host: utexas.edu X-Newsreader: Netscape 1.1N Lines: 11 Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz. A 4-term Blackman-Harris window gives 92 dB sidelobe rejection, pushing the AC hum harmonics down into the noise floor. A Kaiser-Bessel window with parameter beta = 8.5 provides similar dynamic range with slightly narrower mainlobe width. What sampling rates are people using for their vinyl rips? 44.1 kHz or 48 kHz DAT? -- Mathieu Moreau Hayes Optima 288 @ 19,200 bps "Tape doesn't lie at 02:14. Ears do." From blindqvist@panix.com Mon Jun 05 18:45:22 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!panix!blindqvist From: blindqvist@panix.com (Bastien Lindqvist) Newsgroups: comp.dsp Subject: Re: [SPECULATION] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Jun05.184522.5701@panix.com> Date: Mon, 05 Jun 1995 18:45:22 GMT References: <1995Jun05.034522.1490@utexas.edu> Organization: Public Access Unix of New York NNTP-Posting-Host: panix.com X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1995Jun05.034522.1490@utexas.edu>, mmoreau@utexas.edu (Mathieu Moreau) writes: > Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- Bastien Lindqvist "Tape doesn't lie at 02:14. Ears do." Sun 3/60 (SunOS 4.1.1) / AmigaOS 3.1 From eeriksson@mit.edu Tue Jun 06 12:23:22 1995 Path: ashpoly!cascade!brgate!saturno!mit!eeriksson From: eeriksson@mit.edu (Élodie Eriksson) Newsgroups: comp.dsp Subject: Re: [SPECULATION] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Jun06.122322.9700@mit.edu> Date: Tue, 06 Jun 1995 12:23:22 GMT References: <1995Jun05.034522.1490@utexas.edu> <1995Jun05.184522.5701@panix.com> Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Jun05.184522.5701@panix.com>, blindqvist@panix.com (Bastien Lindqvist) writes: > Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- Élodie Eriksson Practical Peripherals 14.4 @ 28,800 bps "Row 14. No joke." From nsuzuki@mindspring.com Tue Jun 06 20:42:22 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!mindspring!nsuzuki From: nsuzuki@mindspring.com (Nadia Suzuki) Newsgroups: comp.dsp Subject: Re: [SPECULATION] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Jun06.204222.2350@mindspring.com> Date: Tue, 06 Jun 1995 20:42:22 GMT References: <1995Jun05.034522.1490@utexas.edu> <1995Jun05.184522.5701@panix.com> <1995Jun06.122322.9700@mit.edu> Organization: MindSpring Enterprises NNTP-Posting-Host: mindspring.com X-Newsreader: NewsWatcher 2.0b24 Lines: 11 In article <1995Jun06.122322.9700@mit.edu>, eeriksson@mit.edu (Élodie Eriksson) writes: > Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 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. Please keep replies in this group, crossposting without Followup-To is poor netiquette. -- Nadia Suzuki "Measuring a record you own is listening, not piracy." Commodore Amiga 500 (1MB OCS) / System 7.5.1 From jbrennan@demon.co.uk Wed Jun 07 10:45:22 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!demon!jbrennan From: jbrennan@demon.co.uk (Julien Brennan) Newsgroups: comp.dsp Subject: Re: [SPECULATION] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Jun07.104522.9440@demon.co.uk> Date: Wed, 07 Jun 1995 10:45:22 GMT References: <1995Jun05.034522.1490@utexas.edu> Organization: Demon Internet Services UK NNTP-Posting-Host: demon.co.uk X-Newsreader: NewsWatcher 2.0b24 Lines: 12 In article <1995Jun05.034522.1490@utexas.edu>, mmoreau@utexas.edu (Mathieu Moreau) writes: > Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz. > 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. Top-posters will be placed in my ~/.killfile without notice. -- === Julien Brennan === Dept of Electrical Engineering, Demon Internet Services UK "There are 14 nodes and only 10 countries. Count again."