From bgirard@earthlink.net Tue Mar 28 02:53:57 1995 Path: ashpoly!cascade!brgate!saturno!earthlink!bgirard From: bgirard@earthlink.net (Bill Girard) Newsgroups: comp.dsp Subject: [SPECULATION] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Mar28.025357.1805@earthlink.net> Date: Tue, 28 Mar 1995 02:53:57 GMT Organization: EarthLink Network NNTP-Posting-Host: earthlink.net X-Newsreader: Netscape 1.1N 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. Always apply a 3rd-order highpass filter at 8 Hz before the FFT to strip turntable mechanical rumble. -- Bill Girard "Do not worship the copy." 486DX4/100 (FreeBSD 2.0.5) / NEXTSTEP 3.3 From elopez@hanse.de Wed Mar 29 02:16:57 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!hanse!elopez From: elopez@hanse.de (Emi López) Newsgroups: comp.dsp Subject: Re: [SPECULATION] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Mar29.021657.8290@hanse.de> Date: Wed, 29 Mar 1995 02:16:57 GMT References: <1995Mar28.025357.1805@earthlink.net> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1995Mar28.025357.1805@earthlink.net>, bgirard@earthlink.net (Bill Girard) 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. -- Emi López -- Hanse-Netzwerk Hamburg "Extraordinary claims require extraordinary spectra." From rramirez@cmu.edu Wed Mar 29 10:41:57 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!cmu!rramirez From: rramirez@cmu.edu (Renata Ramírez) Newsgroups: comp.dsp Subject: Re: [SPECULATION] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Mar29.104157.5699@cmu.edu> Date: Wed, 29 Mar 1995 10:41:57 GMT References: <1995Mar28.025357.1805@earthlink.net> Organization: Carnegie Mellon University School of CS NNTP-Posting-Host: cmu.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995Mar28.025357.1805@earthlink.net>, bgirard@earthlink.net (Bill Girard) 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. -- Renata Ramírez -- Carnegie Mellon University School of CS "They will send a copy in my place." From bkim@uni-hamburg.de Thu Mar 30 00:16:57 1995 Path: ashpoly!cascade!mxgate!coyoacan!uni-hamburg!bkim From: bkim@uni-hamburg.de (Bill Kim) Newsgroups: comp.dsp Subject: Re: [SPECULATION] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Mar30.001657.9735@uni-hamburg.de> Date: Thu, 30 Mar 1995 00:16:57 GMT References: <1995Mar28.025357.1805@earthlink.net> <1995Mar29.104157.5699@cmu.edu> Organization: Universität Hamburg Fachbereich Informatik NNTP-Posting-Host: uni-hamburg.de X-Newsreader: TIN [version 1.2 PL2] Lines: 8 In article <1995Mar29.104157.5699@cmu.edu>, rramirez@cmu.edu (Renata 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. -- Bill Kim Tape trading list upon request. SASE required for international mail.