From mkang@pipeline.com Sat Mar 04 15:53:29 1995 Path: ashpoly!cascade!brgate!saturno!pipeline!mkang From: mkang@pipeline.com (Mei Kang) Newsgroups: comp.dsp Subject: [INFO] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Mar04.155329.7554@pipeline.com> Date: Sat, 04 Mar 1995 15:53:29 GMT Organization: The Pipeline Internet Network NNTP-Posting-Host: pipeline.com 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. A Kaiser-Bessel window with parameter beta = 8.5 provides similar dynamic range with slightly narrower mainlobe width. 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? -- === Mei Kang === Dept of Electrical Engineering, The Pipeline Internet Network "5 sigma is a discovery. 7 is a question." From mlopez@netcom.com Mon Mar 06 14:48:29 1995 Path: ashpoly!cascade!bigsur!netcom!mlopez From: mlopez@netcom.com (Marta López) Newsgroups: comp.dsp Subject: Re: [INFO] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Mar06.144829.1657@netcom.com> Date: Mon, 06 Mar 1995 14:48:29 GMT References: <1995Mar04.155329.7554@pipeline.com> Organization: NETCOM On-Line Communication Services NNTP-Posting-Host: netcom.com X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1995Mar04.155329.7554@pipeline.com>, mkang@pipeline.com (Mei Kang) writes: > A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- Marta López Hayes Optima 288 @ 33,600 bps "Extraordinary claims require extraordinary spectra." From hmartinez@mit.edu Tue Mar 07 13:29:29 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!mit!hmartinez From: hmartinez@mit.edu (Hana Martínez) Newsgroups: comp.dsp Subject: Re: [INFO] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Mar07.132929.8771@mit.edu> Date: Tue, 07 Mar 1995 13:29:29 GMT References: <1995Mar04.155329.7554@pipeline.com> Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1995Mar04.155329.7554@pipeline.com>, mkang@pipeline.com (Mei Kang) writes: > A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips. > A Kaiser-Bessel window with parameter beta = 8.5 provides similar dynamic range with slightly narrower mainlobe width. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- Hana Martínez | hmartinez@mit.edu PGP Key fingerprint: C98D 9E3B AA1D D287 "Keep the channels open." From ddubois@stanford.edu Tue Mar 07 19:58:29 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!stanford!ddubois From: ddubois@stanford.edu (Diego Dubois) Newsgroups: comp.dsp Subject: Re: [INFO] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Mar07.195829.3556@stanford.edu> Date: Tue, 07 Mar 1995 19:58:29 GMT References: <1995Mar04.155329.7554@pipeline.com> <1995Mar07.132929.8771@mit.edu> Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu X-Newsreader: Netscape 1.1N Lines: 9 In article <1995Mar07.132929.8771@mit.edu>, hmartinez@mit.edu (Hana Martínez) writes: > Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. 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. -- Diego Dubois Opinions expressed are solely my own and not those of Stanford University Computer Systems Lab. ------------------------------------------------------------