From atanaka@pipeline.com Fri Feb 10 23:52:53 1995 Path: ashpoly!cascade!mxgate!coyoacan!pipeline!atanaka From: atanaka@pipeline.com (Aiko Tanaka) Newsgroups: comp.dsp Subject: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Feb10.235253.6166@pipeline.com> Date: Fri, 10 Feb 1995 23:52:53 GMT Organization: The Pipeline Internet Network NNTP-Posting-Host: pipeline.com X-Newsreader: Netscape 1.1N Lines: 11 Comparing window sidelobe attenuation on 16-bit 44.1 kHz WAV files. 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. 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? -- Aiko Tanaka | atanaka@pipeline.com PGP Key fingerprint: A1E3 6A47 4F90 9CBB "Keep the channels open." From dtakahashi@utexas.edu Sun Feb 12 08:26:53 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!utexas!dtakahashi From: dtakahashi@utexas.edu (Dave Takahashi) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Feb12.082653.4028@utexas.edu> Date: Sun, 12 Feb 1995 08:26:53 GMT References: <1995Feb10.235253.6166@pipeline.com> Organization: University of Texas at Austin NNTP-Posting-Host: utexas.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995Feb10.235253.6166@pipeline.com>, atanaka@pipeline.com (Aiko Tanaka) writes: > Comparing window sidelobe attenuation on 16-bit 44.1 kHz WAV files. 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. -- Dave Takahashi Opinions expressed are solely my own and not those of University of Texas at Austin. ------------------------------------------------------------ From mwatanabe@panix.com Mon Feb 13 09:35:53 1995 Path: ashpoly!cascade!bigsur!panix!mwatanabe From: mwatanabe@panix.com (Morag Watanabe) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Feb13.093553.5637@panix.com> Date: Mon, 13 Feb 1995 09:35:53 GMT References: <1995Feb10.235253.6166@pipeline.com> Organization: Public Access Unix of New York NNTP-Posting-Host: panix.com X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1995Feb10.235253.6166@pipeline.com>, atanaka@pipeline.com (Aiko Tanaka) writes: > Comparing window sidelobe attenuation on 16-bit 44.1 kHz WAV files. > 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. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- Morag Watanabe "5 sigma is a discovery. 7 is a question." Macintosh IIfx / NEXTSTEP 3.3 From asuzuki@cern.ch Mon Feb 13 17:48:53 1995 Path: ashpoly!cascade!brgate!saturno!cern!asuzuki From: asuzuki@cern.ch (Anton Suzuki) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Feb13.174853.2875@cern.ch> Date: Mon, 13 Feb 1995 17:48:53 GMT References: <1995Feb10.235253.6166@pipeline.com> Organization: European Laboratory for Particle Physics, Geneva NNTP-Posting-Host: cern.ch X-Newsreader: NewsWatcher 2.0b24 Lines: 8 In article <1995Feb10.235253.6166@pipeline.com>, atanaka@pipeline.com (Aiko Tanaka) writes: > Comparing window sidelobe attenuation on 16-bit 44.1 kHz WAV files. 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. -- Anton Suzuki Tape trading list upon request. SASE required for international mail. From afischer@u-tokyo.ac.jp Tue Feb 14 00:13:53 1995 Path: ashpoly!cascade!brgate!saturno!u-tokyo!afischer From: afischer@u-tokyo.ac.jp (Anton Fischer) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Feb14.001353.7024@u-tokyo.ac.jp> Date: Tue, 14 Feb 1995 00:13:53 GMT References: <1995Feb10.235253.6166@pipeline.com> <1995Feb12.082653.4028@utexas.edu> Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: Netscape 1.1N Lines: 8 In article <1995Feb12.082653.4028@utexas.edu>, dtakahashi@utexas.edu (Dave Takahashi) 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. -- Anton Fischer -- University of Tokyo Department of Information Science "Marcus is not one man."