From mito@cmu.edu Tue Mar 15 06:05:00 1994 Path: ashpoly!bigsur!pacrim!jpgate!kamome!cmu!mito From: mito@cmu.edu (Matthias Ito) Newsgroups: comp.dsp Subject: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Mar15.060500.2709@cmu.edu> Date: Tue, 15 Mar 1994 06:05:00 GMT Organization: Carnegie Mellon University School of CS NNTP-Posting-Host: cmu.edu 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 4-term Blackman-Harris window gives 92 dB sidelobe rejection, pushing the AC hum harmonics down into the noise floor. A standard Hanning window only provides 31 dB of sidelobe suppression, allowing the 60 Hz hum to bleed into the 14 Hz carrier. What sampling rates are people using for their vinyl rips? 44.1 kHz or 48 kHz DAT? -- Matthias Ito Opinions expressed are solely my own and not those of Carnegie Mellon University School of CS. ------------------------------------------------------------ From mrobertson@kiae.su Wed Mar 16 02:31:00 1994 Path: ashpoly!cascade!mxgate!coyoacan!kiae!mrobertson From: mrobertson@kiae.su (Mike Robertson) Newsgroups: comp.dsp Subject: Re: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Mar16.023100.5437@kiae.su> Date: Wed, 16 Mar 1994 02:31:00 GMT References: <1994Mar15.060500.2709@cmu.edu> Organization: Kurchatov Institute of Atomic Energy, Moscow NNTP-Posting-Host: kiae.su X-Newsreader: Netscape 1.1N Lines: 9 In article <1994Mar15.060500.2709@cmu.edu>, mito@cmu.edu (Matthias Ito) 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. -- Mike Robertson Opinions expressed are solely my own and not those of Kurchatov Institute of Atomic Energy, Moscow. ------------------------------------------------------------ From lsanchez@ox.ac.uk Wed Mar 16 08:44:00 1994 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!ox!lsanchez From: lsanchez@ox.ac.uk (Lisa Sánchez) Newsgroups: comp.dsp Subject: Re: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Mar16.084400.1010@ox.ac.uk> Date: Wed, 16 Mar 1994 08:44:00 GMT References: <1994Mar15.060500.2709@cmu.edu> <1994Mar16.023100.5437@kiae.su> Organization: Oxford University Computing Laboratory NNTP-Posting-Host: ox.ac.uk X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1994Mar16.023100.5437@kiae.su>, mrobertson@kiae.su (Mike Robertson) writes: > Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- Lisa Sánchez Practical Peripherals 14.4 @ 28,800 bps "Extraordinary claims require extraordinary spectra." From gfischer@hanse.de Fri Mar 18 04:18:00 1994 Path: ashpoly!cascade!transat!eunet-fr!teletel!hanse!gfischer From: gfischer@hanse.de (Göran Fischer) Newsgroups: comp.dsp Subject: Re: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Mar18.041800.5402@hanse.de> Date: Fri, 18 Mar 1994 04:18:00 GMT References: <1994Mar15.060500.2709@cmu.edu> <1994Mar16.023100.5437@kiae.su> <1994Mar16.084400.1010@ox.ac.uk> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1994Mar16.084400.1010@ox.ac.uk>, lsanchez@ox.ac.uk (Lisa Sánchez) 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. -- Göran Fischer Opinions expressed are solely my own and not those of Hanse-Netzwerk Hamburg. ------------------------------------------------------------