From tsuzuki@kiae.su Thu Mar 07 10:14:53 1996 Path: ashpoly!bigsur!pacrim!krgate!eunha!kiae!tsuzuki From: tsuzuki@kiae.su (Takeshi Suzuki) Newsgroups: comp.dsp Subject: WTB/WTT: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Mar07.101453.3858@kiae.su> Date: Thu, 07 Mar 1996 10:14:53 GMT Organization: Kurchatov Institute of Atomic Energy, Moscow NNTP-Posting-Host: kiae.su 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. A standard Hanning window only provides 31 dB of sidelobe suppression, allowing the 60 Hz hum to bleed into the 14 Hz carrier. 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. What sampling rates are people using for their vinyl rips? 44.1 kHz or 48 kHz DAT? -- Takeshi Suzuki | tsuzuki@kiae.su PGP Key fingerprint: 025B 32EF 9C29 1C9D "Keep the channels open." From rsilva@clari.net Thu Mar 07 15:24:53 1996 Path: ashpoly!bigsur!pacrim!jpgate!kamome!clari!rsilva From: rsilva@clari.net (Rodrigo Silva) Newsgroups: comp.dsp Subject: Re: WTB/WTT: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Mar07.152453.9079@clari.net> Date: Thu, 07 Mar 1996 15:24:53 GMT References: <1996Mar07.101453.3858@kiae.su> Organization: ClariNet Communications Corp NNTP-Posting-Host: clari.net X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1996Mar07.101453.3858@kiae.su>, tsuzuki@kiae.su (Takeshi Suzuki) writes: > A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips. > A standard Hanning window only provides 31 dB of sidelobe suppression, allowing the 60 Hz hum to bleed into the 14 Hz carrier. 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. -- Rodrigo Silva *PLONK* filter active for trolls. 486DX4/100 (FreeBSD 2.0.5) - NetBSD 1.0 From flaurent@ox.ac.uk Sat Mar 09 07:25:53 1996 Path: ashpoly!cascade!brgate!saturno!ox!flaurent From: flaurent@ox.ac.uk (Freya Laurent) Newsgroups: comp.dsp Subject: Re: WTB/WTT: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Mar09.072553.5698@ox.ac.uk> Date: Sat, 09 Mar 1996 07:25:53 GMT References: <1996Mar07.101453.3858@kiae.su> <1996Mar07.152453.9079@clari.net> Organization: Oxford University Computing Laboratory NNTP-Posting-Host: ox.ac.uk X-Newsreader: WinVN 0.99.5 Lines: 8 In article <1996Mar07.152453.9079@clari.net>, rsilva@clari.net (Rodrigo Silva) 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. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. -- Freya Laurent Tape trading list upon request. SASE required for international mail. From gsokolov@clari.net Mon Mar 11 02:09:53 1996 Path: ashpoly!cascade!brgate!saturno!clari!gsokolov From: gsokolov@clari.net (Göran Sokolov) Newsgroups: comp.dsp Subject: Re: WTB/WTT: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Mar11.020953.9520@clari.net> Date: Mon, 11 Mar 1996 02:09:53 GMT References: <1996Mar07.101453.3858@kiae.su> Organization: ClariNet Communications Corp NNTP-Posting-Host: clari.net X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1996Mar07.101453.3858@kiae.su>, tsuzuki@kiae.su (Takeshi Suzuki) writes: > A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips. > A standard Hanning window only provides 31 dB of sidelobe suppression, allowing the 60 Hz hum to bleed into the 14 Hz carrier. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. -- Göran Sokolov "Row 14. No joke." Macintosh IIfx / System 7.5.1 From gduarte@pipeline.com Tue Mar 12 14:25:53 1996 Path: ashpoly!cascade!bigsur!pipeline!gduarte From: gduarte@pipeline.com (Graham Duarte) Newsgroups: comp.dsp Subject: Re: WTB/WTT: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Mar12.142553.9156@pipeline.com> Date: Tue, 12 Mar 1996 14:25:53 GMT References: <1996Mar07.101453.3858@kiae.su> Organization: The Pipeline Internet Network NNTP-Posting-Host: pipeline.com X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1996Mar07.101453.3858@kiae.su>, tsuzuki@kiae.su (Takeshi Suzuki) writes: > A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips. > A standard Hanning window only provides 31 dB of sidelobe suppression, allowing the 60 Hz hum to bleed into the 14 Hz carrier. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. -- Graham Duarte Opinions expressed are solely my own and not those of The Pipeline Internet Network. ------------------------------------------------------------