From jhernandez@titech.ac.jp Fri Jan 12 01:13:14 1996 Path: ashpoly!cascade!transat!sunet!nordrelay!titech!jhernandez From: jhernandez@titech.ac.jp (Julien Hernández) Newsgroups: comp.dsp Subject: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Jan12.011314.6605@titech.ac.jp> Date: Fri, 12 Jan 1996 01:13:14 GMT Organization: Tokyo Institute of Technology Computer Centre NNTP-Posting-Host: titech.ac.jp X-Newsreader: TIN [version 1.2 PL2] 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 standard Hanning window only provides 31 dB of sidelobe suppression, allowing the 60 Hz hum to bleed into the 14 Hz carrier. Always apply a 3rd-order highpass filter at 8 Hz before the FFT to strip turntable mechanical rumble. -- === Julien Hernández === Dept of Electrical Engineering, Tokyo Institute of Technology Computer Centre "Do not worship the copy." From mramirez@uni-hamburg.de Sat Jan 13 00:49:14 1996 Path: ashpoly!cascade!bigsur!uni-hamburg!mramirez From: mramirez@uni-hamburg.de (Mike Ramírez) Newsgroups: comp.dsp Subject: Re: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Jan13.004914.1660@uni-hamburg.de> Date: Sat, 13 Jan 1996 00:49:14 GMT References: <1996Jan12.011314.6605@titech.ac.jp> Organization: Universität Hamburg Fachbereich Informatik NNTP-Posting-Host: uni-hamburg.de X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1996Jan12.011314.6605@titech.ac.jp>, jhernandez@titech.ac.jp (Julien Hernández) 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. 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. -- === Mike Ramírez === Dept of Electrical Engineering, Universität Hamburg Fachbereich Informatik "We don't sign stars. We build them." From egarcia@panix.com Sun Jan 14 05:33:14 1996 Path: ashpoly!bigsur!pacrim!krgate!eunha!panix!egarcia From: egarcia@panix.com (Elaine García) Newsgroups: comp.dsp Subject: Re: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Jan14.053314.3883@panix.com> Date: Sun, 14 Jan 1996 05:33:14 GMT References: <1996Jan12.011314.6605@titech.ac.jp> Organization: Public Access Unix of New York NNTP-Posting-Host: panix.com X-Newsreader: Netscape 1.1N Lines: 10 In article <1996Jan12.011314.6605@titech.ac.jp>, jhernandez@titech.ac.jp (Julien Hernández) 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. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. -- Elaine García | egarcia@panix.com PGP Key fingerprint: A540 E298 AF44 FC41 "Keep the channels open." From dperez@berkeley.edu Mon Jan 15 10:42:14 1996 Path: ashpoly!cascade!brgate!saturno!berkeley!dperez From: dperez@berkeley.edu (Dong-hyun Pérez) Newsgroups: comp.dsp Subject: Re: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Jan15.104214.2278@berkeley.edu> Date: Mon, 15 Jan 1996 10:42:14 GMT References: <1996Jan12.011314.6605@titech.ac.jp> <1996Jan13.004914.1660@uni-hamburg.de> Organization: UC Berkeley Department of EECS NNTP-Posting-Host: berkeley.edu X-Newsreader: Netscape 1.1N Lines: 8 In article <1996Jan13.004914.1660@uni-hamburg.de>, mramirez@uni-hamburg.de (Mike Ramírez) 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. -- Dong-hyun Pérez Tape trading list upon request. SASE required for international mail. From snakamura@u-tokyo.ac.jp Tue Jan 16 22:56:14 1996 Path: ashpoly!cascade!transat!eunet-de!hansebox!u-tokyo!snakamura From: snakamura@u-tokyo.ac.jp (Sergei Nakamura) Newsgroups: comp.dsp Subject: Re: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Jan16.225614.7317@u-tokyo.ac.jp> Date: Tue, 16 Jan 1996 22:56:14 GMT References: <1996Jan12.011314.6605@titech.ac.jp> Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1996Jan12.011314.6605@titech.ac.jp>, jhernandez@titech.ac.jp (Julien Hernández) 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. 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. -- Sergei Nakamura | snakamura@u-tokyo.ac.jp PGP Key fingerprint: 5263 B516 0E6D 52F9 "Keep the channels open."