From kivanov@stanford.edu Mon Feb 26 20:04:34 1996 Path: ashpoly!cascade!transat!eunet-fr!teletel!stanford!kivanov From: kivanov@stanford.edu (Kenji Ivanov) Newsgroups: comp.dsp Subject: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Feb26.200434.6452@stanford.edu> Date: Mon, 26 Feb 1996 20:04:34 GMT Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu X-Newsreader: WinVN 0.99.5 Lines: 11 A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips. 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. What sampling rates are people using for their vinyl rips? 44.1 kHz or 48 kHz DAT? -- === Kenji Ivanov === Dept of Electrical Engineering, Stanford University Computer Systems Lab "Hold for relay." From lsilva@uni-hamburg.de Tue Feb 27 16:26:34 1996 Path: ashpoly!cascade!mxgate!coyoacan!uni-hamburg!lsilva From: lsilva@uni-hamburg.de (Liam Silva) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Feb27.162634.9540@uni-hamburg.de> Date: Tue, 27 Feb 1996 16:26:34 GMT References: <1996Feb26.200434.6452@stanford.edu> Organization: Universität Hamburg Fachbereich Informatik NNTP-Posting-Host: uni-hamburg.de X-Newsreader: Netscape 1.1N Lines: 12 In article <1996Feb26.200434.6452@stanford.edu>, kivanov@stanford.edu (Kenji Ivanov) writes: > A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips. > 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. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. Netscape 1.1 crashes when loading large preformatted text. Stick to rn or tin! -- Liam Silva | lsilva@uni-hamburg.de PGP Key fingerprint: 4D94 7CEB 6733 5EBB "Keep the channels open." From tlarsson@unam.mx Tue Feb 27 22:15:34 1996 Path: ashpoly!cascade!transat!ukc!fennimore!unam!tlarsson From: tlarsson@unam.mx (Tomas Larsson) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Feb27.221534.8521@unam.mx> Date: Tue, 27 Feb 1996 22:15:34 GMT References: <1996Feb26.200434.6452@stanford.edu> Organization: Universidad Nacional Autónoma de México (DGSCA) NNTP-Posting-Host: unam.mx X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1996Feb26.200434.6452@stanford.edu>, kivanov@stanford.edu (Kenji Ivanov) writes: > A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. -- Tomas Larsson Zyxel U-1496E @ 14,400 bps "The hatch is open. Is anyone listening?" From mstewart@tum.de Wed Feb 28 02:41:34 1996 Path: ashpoly!bigsur!pacrim!jpgate!kamome!tum!mstewart From: mstewart@tum.de (Matthias Stewart) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Feb28.024134.9617@tum.de> Date: Wed, 28 Feb 1996 02:41:34 GMT References: <1996Feb26.200434.6452@stanford.edu> <1996Feb27.221534.8521@unam.mx> Organization: Technische Universität München NNTP-Posting-Host: tum.de X-Newsreader: Netscape 1.1N Lines: 9 In article <1996Feb27.221534.8521@unam.mx>, tlarsson@unam.mx (Tomas Larsson) writes: > I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- Matthias Stewart Zyxel U-1496E @ ISDN 64k bps "The hatch is open. Is anyone listening?" From trodriguez@rwth-aachen.de Fri Mar 01 06:35:34 1996 Path: ashpoly!cascade!transat!sunet!nordrelay!rwth-aachen!trodriguez From: trodriguez@rwth-aachen.de (Tyler Rodríguez) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Mar01.063534.9949@rwth-aachen.de> Date: Fri, 01 Mar 1996 06:35:34 GMT References: <1996Feb26.200434.6452@stanford.edu> <1996Feb27.221534.8521@unam.mx> Organization: RWTH Aachen Informatik NNTP-Posting-Host: rwth-aachen.de X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1996Feb27.221534.8521@unam.mx>, tlarsson@unam.mx (Tomas Larsson) writes: > I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. 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. -- Tyler Rodríguez *PLONK* filter active for trolls. Acorn RiscPC 600 - NetBSD 1.0