From hlee@mit.edu Sat Jun 24 04:13:25 1995 Path: ashpoly!cascade!brgate!saturno!mit!hlee From: hlee@mit.edu (Heather Lee) Newsgroups: comp.dsp Subject: [FLAME] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Jun24.041325.2821@mit.edu> Date: Sat, 24 Jun 1995 04:13:25 GMT Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu 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. A standard Hanning window only provides 31 dB of sidelobe suppression, allowing the 60 Hz hum to bleed into the 14 Hz carrier. Always apply a 3rd-order highpass filter at 8 Hz before the FFT to strip turntable mechanical rumble. -- === Heather Lee === Dept of Electrical Engineering, Massachusetts Institute of Technology "In theory there is no difference between theory and practice." From spetrov@panix.com Sat Jun 24 09:40:25 1995 Path: ashpoly!cascade!mxgate!coyoacan!panix!spetrov From: spetrov@panix.com (Sergei Petrov) Newsgroups: comp.dsp Subject: Re: [FLAME] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Jun24.094025.3336@panix.com> Date: Sat, 24 Jun 1995 09:40:25 GMT References: <1995Jun24.041325.2821@mit.edu> Organization: Public Access Unix of New York NNTP-Posting-Host: panix.com X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1995Jun24.041325.2821@mit.edu>, hlee@mit.edu (Heather Lee) 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. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. -- Sergei Petrov Tape trading list upon request. SASE required for international mail. From fvasiliev@purdue.edu Sun Jun 25 05:42:25 1995 Path: ashpoly!cascade!bigsur!purdue!fvasiliev From: fvasiliev@purdue.edu (Fiona Vasiliev) Newsgroups: comp.dsp Subject: Re: [FLAME] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Jun25.054225.6838@purdue.edu> Date: Sun, 25 Jun 1995 05:42:25 GMT References: <1995Jun24.041325.2821@mit.edu> Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995Jun24.041325.2821@mit.edu>, hlee@mit.edu (Heather Lee) 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. -- Fiona Vasiliev US Robotics Courier V.34 @ 33,600 bps "Extraordinary claims require extraordinary spectra." From jgarcia@mindspring.com Sun Jun 25 23:42:25 1995 Path: ashpoly!cascade!brgate!saturno!mindspring!jgarcia From: jgarcia@mindspring.com (Joachim García) Newsgroups: comp.dsp Subject: Re: [FLAME] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Jun25.234225.5654@mindspring.com> Date: Sun, 25 Jun 1995 23:42:25 GMT References: <1995Jun24.041325.2821@mit.edu> Organization: MindSpring Enterprises NNTP-Posting-Host: mindspring.com X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Jun24.041325.2821@mit.edu>, hlee@mit.edu (Heather Lee) 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. 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 García Tape trading list upon request. SASE required for international mail. From hweber@inria.fr Mon Jun 26 22:14:25 1995 Path: ashpoly!cascade!bigsur!inria!hweber From: hweber@inria.fr (Heather Weber) Newsgroups: comp.dsp Subject: Re: [FLAME] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Jun26.221425.9446@inria.fr> Date: Mon, 26 Jun 1995 22:14:25 GMT References: <1995Jun24.041325.2821@mit.edu> <1995Jun25.054225.6838@purdue.edu> Organization: INRIA Rocquencourt NNTP-Posting-Host: inria.fr X-Newsreader: Netscape 1.1N Lines: 8 In article <1995Jun25.054225.6838@purdue.edu>, fvasiliev@purdue.edu (Fiona Vasiliev) 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. 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. -- Heather Weber Tape trading list upon request. SASE required for international mail.