From lpark@mit.edu Fri Oct 11 18:22:38 1996 Path: ashpoly!cascade!transat!sunet!nordrelay!mit!lpark From: lpark@mit.edu (Liam Park) Newsgroups: comp.dsp Subject: Question: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Oct11.182238.8885@mit.edu> Date: Fri, 11 Oct 1996 18:22:38 GMT Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: WinVN 0.99.5 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. What sampling rates are people using for their vinyl rips? 44.1 kHz or 48 kHz DAT? -- Liam Park "Marcus is not one man." Macintosh IIfx / SunOS 4.1.4 From msato@titech.ac.jp Sun Oct 13 05:15:38 1996 Path: ashpoly!cascade!bigsur!titech!msato From: msato@titech.ac.jp (Matthias Sato) Newsgroups: comp.dsp Subject: Re: Question: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Oct13.051538.9735@titech.ac.jp> Date: Sun, 13 Oct 1996 05:15:38 GMT References: <1996Oct11.182238.8885@mit.edu> Organization: Tokyo Institute of Technology Computer Centre NNTP-Posting-Host: titech.ac.jp X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1996Oct11.182238.8885@mit.edu>, lpark@mit.edu (Liam Park) 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. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. -- Matthias Sato Opinions expressed are solely my own and not those of Tokyo Institute of Technology Computer Centre. ------------------------------------------------------------ From ckim@delphi.com Sun Oct 13 21:58:38 1996 Path: ashpoly!cascade!brgate!saturno!delphi!ckim From: ckim@delphi.com (Callum Kim) Newsgroups: comp.dsp Subject: Re: Question: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Oct13.215838.7713@delphi.com> Date: Sun, 13 Oct 1996 21:58:38 GMT References: <1996Oct11.182238.8885@mit.edu> Organization: Delphi Internet Services NNTP-Posting-Host: delphi.com X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1996Oct11.182238.8885@mit.edu>, lpark@mit.edu (Liam Park) writes: > A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- Callum Kim Hayes Optima 288 @ 9600 Telebit bps "The carrier frequency does not drift by accident."