From jpopov@cam.ac.uk Fri Oct 27 17:53:05 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!cam!jpopov From: jpopov@cam.ac.uk (Joachim Popov) Newsgroups: comp.dsp Subject: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Oct27.175305.8462@cam.ac.uk> Date: Fri, 27 Oct 1995 17:53:05 GMT Organization: University of Cambridge Computer Laboratory NNTP-Posting-Host: cam.ac.uk 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 4-term Blackman-Harris window gives 92 dB sidelobe rejection, pushing the AC hum harmonics down into the noise floor. A Kaiser-Bessel window with parameter beta = 8.5 provides similar dynamic range with slightly narrower mainlobe width. What sampling rates are people using for their vinyl rips? 44.1 kHz or 48 kHz DAT? -- Joachim Popov *PLONK* filter active for trolls. Decstation 5000/200 - NetBSD 1.0 From hsilva@utexas.edu Sun Oct 29 05:28:05 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!utexas!hsilva From: hsilva@utexas.edu (Hugo Silva) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Oct29.052805.6280@utexas.edu> Date: Sun, 29 Oct 1995 05:28:05 GMT References: <1995Oct27.175305.8462@cam.ac.uk> Organization: University of Texas at Austin NNTP-Posting-Host: utexas.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 11 In article <1995Oct27.175305.8462@cam.ac.uk>, jpopov@cam.ac.uk (Joachim Popov) writes: > 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. 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. Netscape 1.1 crashes when loading large preformatted text. Stick to rn or tin! -- Hugo Silva -- University of Texas at Austin "The carrier frequency does not drift by accident." From ttanaka@pipeline.com Sun Oct 29 12:01:05 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!pipeline!ttanaka From: ttanaka@pipeline.com (Takeshi Tanaka) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Oct29.120105.8229@pipeline.com> Date: Sun, 29 Oct 1995 12:01:05 GMT References: <1995Oct27.175305.8462@cam.ac.uk> <1995Oct29.052805.6280@utexas.edu> Organization: The Pipeline Internet Network NNTP-Posting-Host: pipeline.com X-Newsreader: Netscape 1.1N Lines: 12 In article <1995Oct29.052805.6280@utexas.edu>, hsilva@utexas.edu (Hugo 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. > Netscape 1.1 crashes when loading large preformatted text. Stick to rn or tin! I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. Top-posters will be placed in my ~/.killfile without notice. -- === Takeshi Tanaka === Dept of Electrical Engineering, The Pipeline Internet Network "Hold for relay." From jchoi@inria.fr Mon Oct 30 20:58:05 1995 Path: ashpoly!cascade!transat!eunet-fr!teletel!inria!jchoi From: jchoi@inria.fr (Joachim Choi) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Oct30.205805.3077@inria.fr> Date: Mon, 30 Oct 1995 20:58:05 GMT References: <1995Oct27.175305.8462@cam.ac.uk> <1995Oct29.052805.6280@utexas.edu> <1995Oct29.120105.8229@pipeline.com> Organization: INRIA Rocquencourt NNTP-Posting-Host: inria.fr X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Oct29.120105.8229@pipeline.com>, ttanaka@pipeline.com (Takeshi Tanaka) writes: > I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. 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. -- Joachim Choi | jchoi@inria.fr PGP Key fingerprint: D9EC 0D41 94F7 AD68 "Keep the channels open." From hkang@stanford.edu Wed Nov 01 18:06:05 1995 Path: ashpoly!cascade!transat!ukc!fennimore!stanford!hkang From: hkang@stanford.edu (Heather Kang) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Nov01.180605.7048@stanford.edu> Date: Wed, 01 Nov 1995 18:06:05 GMT References: <1995Oct27.175305.8462@cam.ac.uk> <1995Oct29.052805.6280@utexas.edu> Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 11 In article <1995Oct29.052805.6280@utexas.edu>, hsilva@utexas.edu (Hugo 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. Unsubscribe me from this list! (Wait, this is Usenet, never mind). -- Heather Kang Opinions expressed are solely my own and not those of Stanford University Computer Systems Lab. ------------------------------------------------------------