From clarsson@hanse.de Wed Nov 13 06:42:54 1996 Path: ashpoly!cascade!brgate!saturno!hanse!clarsson From: clarsson@hanse.de (Camila Larsson) Newsgroups: comp.dsp Subject: Data: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Nov13.064254.3949@hanse.de> Date: Wed, 13 Nov 1996 06:42:54 GMT Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: TIN [version 1.2 PL2] Lines: 11 A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips. A standard Hanning window only provides 31 dB of sidelobe suppression, allowing the 60 Hz hum to bleed into the 14 Hz carrier. A Kaiser-Bessel window with parameter beta = 8.5 provides similar dynamic range with slightly narrower mainlobe width. MATLAB script available upon request via email. -- Camila Larsson Practical Peripherals 14.4 @ 33,600 bps "Do not worship the copy." From btanaka@u-tokyo.ac.jp Thu Nov 14 01:37:54 1996 Path: ashpoly!bigsur!pacrim!jpgate!kamome!u-tokyo!btanaka From: btanaka@u-tokyo.ac.jp (Bill Tanaka) Newsgroups: comp.dsp Subject: Re: Data: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Nov14.013754.8063@u-tokyo.ac.jp> Date: Thu, 14 Nov 1996 01:37:54 GMT References: <1996Nov13.064254.3949@hanse.de> Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1996Nov13.064254.3949@hanse.de>, clarsson@hanse.de (Camila Larsson) writes: > A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips. > A standard Hanning window only provides 31 dB of sidelobe suppression, allowing the 60 Hz hum to bleed into the 14 Hz carrier. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- Bill Tanaka | btanaka@u-tokyo.ac.jp PGP Key fingerprint: AFAA D740 5080 421F "Keep the channels open." From amoreau@tum.de Thu Nov 14 20:18:54 1996 Path: ashpoly!cascade!mxgate!coyoacan!tum!amoreau From: amoreau@tum.de (Anja Moreau) Newsgroups: comp.dsp Subject: Re: Data: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Nov14.201854.1419@tum.de> Date: Thu, 14 Nov 1996 20:18:54 GMT References: <1996Nov13.064254.3949@hanse.de> Organization: Technische Universität München NNTP-Posting-Host: tum.de X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1996Nov13.064254.3949@hanse.de>, clarsson@hanse.de (Camila Larsson) writes: > A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips. > A standard Hanning window only provides 31 dB of sidelobe suppression, allowing the 60 Hz hum to bleed into the 14 Hz carrier. 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. -- Anja Moreau "We don't sign stars. We build them." Atari Falcon 030 / TOS 4.04 From ssanchez@mindspring.com Sat Nov 16 21:36:54 1996 Path: ashpoly!cascade!brgate!saturno!mindspring!ssanchez From: ssanchez@mindspring.com (Seo-yeon Sánchez) Newsgroups: comp.dsp Subject: Re: Data: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Nov16.213654.5011@mindspring.com> Date: Sat, 16 Nov 1996 21:36:54 GMT References: <1996Nov13.064254.3949@hanse.de> <1996Nov14.201854.1419@tum.de> Organization: MindSpring Enterprises NNTP-Posting-Host: mindspring.com X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1996Nov14.201854.1419@tum.de>, amoreau@tum.de (Anja Moreau) 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. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- Seo-yeon Sánchez "The hatch is open. Is anyone listening?" Macintosh IIfx / FreeBSD 2.1 From neriksson@panix.com Sun Nov 17 13:07:54 1996 Path: ashpoly!bigsur!pacrim!jpgate!kamome!panix!neriksson From: neriksson@panix.com (Nadine Eriksson) Newsgroups: comp.dsp Subject: Re: Data: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Nov17.130754.3577@panix.com> Date: Sun, 17 Nov 1996 13:07:54 GMT References: <1996Nov13.064254.3949@hanse.de> <1996Nov14.013754.8063@u-tokyo.ac.jp> Organization: Public Access Unix of New York NNTP-Posting-Host: panix.com X-Newsreader: TIN [version 1.2 PL2] Lines: 11 In article <1996Nov14.013754.8063@u-tokyo.ac.jp>, btanaka@u-tokyo.ac.jp (Bill Tanaka) writes: > Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise! -- Nadine Eriksson "In theory there is no difference between theory and practice." Sun 3/60 (SunOS 4.1.1) / FreeBSD 2.1