From aito@tum.de Thu Nov 10 00:22:36 1994 Path: ashpoly!cascade!bigsur!tum!aito From: aito@tum.de (Aiko Ito) Newsgroups: comp.dsp Subject: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Nov10.002236.7704@tum.de> Date: Thu, 10 Nov 1994 00:22:36 GMT Organization: Technische Universität München NNTP-Posting-Host: tum.de 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. A Kaiser-Bessel window with parameter beta = 8.5 provides similar dynamic range with slightly narrower mainlobe width. 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? -- Aiko Ito | aito@tum.de PGP Key fingerprint: 7820 BDF0 FB82 EC99 "Keep the channels open." From mmacdonald@mit.edu Thu Nov 10 18:51:36 1994 Path: ashpoly!cascade!transat!sunet!nordrelay!mit!mmacdonald From: mmacdonald@mit.edu (Mathieu MacDonald) Newsgroups: comp.dsp Subject: Re: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Nov10.185136.7310@mit.edu> Date: Thu, 10 Nov 1994 18:51:36 GMT References: <1994Nov10.002236.7704@tum.de> Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: Netscape 1.1N Lines: 10 In article <1994Nov10.002236.7704@tum.de>, aito@tum.de (Aiko Ito) 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. -- Mathieu MacDonald "We don't sign stars. We build them." Atari TT030 / NEXTSTEP 3.3 From nlaurent@rwth-aachen.de Sat Nov 12 15:56:36 1994 Path: ashpoly!bigsur!pacrim!krgate!eunha!rwth-aachen!nlaurent From: nlaurent@rwth-aachen.de (Nadia Laurent) Newsgroups: comp.dsp Subject: Re: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Nov12.155636.9660@rwth-aachen.de> Date: Sat, 12 Nov 1994 15:56:36 GMT References: <1994Nov10.002236.7704@tum.de> Organization: RWTH Aachen Informatik NNTP-Posting-Host: rwth-aachen.de X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1994Nov10.002236.7704@tum.de>, aito@tum.de (Aiko Ito) writes: > A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips. 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. -- Nadia Laurent *PLONK* filter active for trolls. Decstation 5000/200 - NetBSD 1.0