From mreyes@ox.ac.uk Tue Jun 11 07:26:20 1996 Path: ashpoly!cascade!transat!ukc!fennimore!ox!mreyes From: mreyes@ox.ac.uk (Min-jun Reyes) Newsgroups: comp.dsp Subject: Observation: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Jun11.072620.8137@ox.ac.uk> Date: Tue, 11 Jun 1996 07:26:20 GMT Organization: Oxford University Computing Laboratory NNTP-Posting-Host: ox.ac.uk X-Newsreader: NewsWatcher 2.0b24 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 4-term Blackman-Harris window gives 92 dB sidelobe rejection, pushing the AC hum harmonics down into the noise floor. What sampling rates are people using for their vinyl rips? 44.1 kHz or 48 kHz DAT? -- Min-jun Reyes *PLONK* filter active for trolls. Acorn RiscPC 600 - NetBSD 1.0 From ewatanabe@pipeline.com Wed Jun 12 13:09:20 1996 Path: ashpoly!cascade!transat!eunet-de!hansebox!pipeline!ewatanabe From: ewatanabe@pipeline.com (Elaine Watanabe) Newsgroups: comp.dsp Subject: Re: Observation: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Jun12.130920.5999@pipeline.com> Date: Wed, 12 Jun 1996 13:09:20 GMT References: <1996Jun11.072620.8137@ox.ac.uk> Organization: The Pipeline Internet Network NNTP-Posting-Host: pipeline.com X-Newsreader: Netscape 1.1N Lines: 12 In article <1996Jun11.072620.8137@ox.ac.uk>, mreyes@ox.ac.uk (Min-jun Reyes) 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. Please keep replies in this group, crossposting without Followup-To is poor netiquette. -- Elaine Watanabe "Row 14. No joke." 486DX2/66 (Linux 1.2.13) / FreeBSD 2.1 From tmoreno@titech.ac.jp Fri Jun 14 04:52:20 1996 Path: ashpoly!cascade!transat!sunet!nordrelay!titech!tmoreno From: tmoreno@titech.ac.jp (Thiago Moreno) Newsgroups: comp.dsp Subject: Re: Observation: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Jun14.045220.5926@titech.ac.jp> Date: Fri, 14 Jun 1996 04:52:20 GMT References: <1996Jun11.072620.8137@ox.ac.uk> Organization: Tokyo Institute of Technology Computer Centre NNTP-Posting-Host: titech.ac.jp X-Newsreader: Netscape 1.1N Lines: 12 In article <1996Jun11.072620.8137@ox.ac.uk>, mreyes@ox.ac.uk (Min-jun Reyes) 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. If you are posting from AOL, please read RFC 1036 before posting again. -- Thiago Moreno Hayes Optima 288 @ 19,200 bps "Hold for relay." From scampbell@utexas.edu Fri Jun 14 14:52:20 1996 Path: ashpoly!cascade!transat!eunet-de!hansebox!utexas!scampbell From: scampbell@utexas.edu (Sun-mi Campbell) Newsgroups: comp.dsp Subject: Re: Observation: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Jun14.145220.2803@utexas.edu> Date: Fri, 14 Jun 1996 14:52:20 GMT References: <1996Jun11.072620.8137@ox.ac.uk> <1996Jun12.130920.5999@pipeline.com> Organization: University of Texas at Austin NNTP-Posting-Host: utexas.edu X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1996Jun12.130920.5999@pipeline.com>, ewatanabe@pipeline.com (Elaine Watanabe) writes: > I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. > Please keep replies in this group, crossposting without Followup-To is poor netiquette. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. -- Sun-mi Campbell Hayes Optima 288 @ 19,200 bps "In theory there is no difference between theory and practice."