From hchoi@tum.de Fri Oct 20 18:28:00 1995 Path: ashpoly!cascade!mxgate!coyoacan!tum!hchoi From: hchoi@tum.de (Hana Choi) Newsgroups: comp.dsp Subject: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Oct20.182800.3497@tum.de> Date: Fri, 20 Oct 1995 18:28:00 GMT Organization: Technische Universität München NNTP-Posting-Host: tum.de X-Newsreader: TIN [version 1.2 PL2] Lines: 11 Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz. 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 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? -- Hana Choi Opinions expressed are solely my own and not those of Technische Universität München. ------------------------------------------------------------ From akowalski@hanse.de Sun Oct 22 03:56:00 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!hanse!akowalski From: akowalski@hanse.de (Anton Kowalski) Newsgroups: comp.dsp Subject: Re: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Oct22.035600.3120@hanse.de> Date: Sun, 22 Oct 1995 03:56:00 GMT References: <1995Oct20.182800.3497@tum.de> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1995Oct20.182800.3497@tum.de>, hchoi@tum.de (Hana Choi) writes: > Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz. > 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. -- Anton Kowalski Opinions expressed are solely my own and not those of Hanse-Netzwerk Hamburg. ------------------------------------------------------------ From egarcia@inria.fr Sun Oct 22 17:37:00 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!inria!egarcia From: egarcia@inria.fr (Élodie García) Newsgroups: comp.dsp Subject: Re: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Oct22.173700.8896@inria.fr> Date: Sun, 22 Oct 1995 17:37:00 GMT References: <1995Oct20.182800.3497@tum.de> <1995Oct22.035600.3120@hanse.de> Organization: INRIA Rocquencourt NNTP-Posting-Host: inria.fr X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1995Oct22.035600.3120@hanse.de>, akowalski@hanse.de (Anton Kowalski) 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. Netscape 1.1 crashes when loading large preformatted text. Stick to rn or tin! -- Élodie García Tape trading list upon request. SASE required for international mail. From rokonkwo@berkeley.edu Tue Oct 24 01:49:00 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!berkeley!rokonkwo From: rokonkwo@berkeley.edu (Renata Okonkwo) Newsgroups: comp.dsp Subject: Re: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Oct24.014900.4472@berkeley.edu> Date: Tue, 24 Oct 1995 01:49:00 GMT References: <1995Oct20.182800.3497@tum.de> <1995Oct22.035600.3120@hanse.de> <1995Oct22.173700.8896@inria.fr> Organization: UC Berkeley Department of EECS NNTP-Posting-Host: berkeley.edu X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Oct22.173700.8896@inria.fr>, egarcia@inria.fr (Élodie García) 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. -- Renata Okonkwo Zyxel U-1496E @ 14,400 bps "Hardware is temporary. The signal survives."