From vsilva@illinois.edu Wed Jun 22 06:04:29 1994 Path: ashpoly!cascade!transat!eunet-de!hansebox!illinois!vsilva From: vsilva@illinois.edu (Valeria Silva) Newsgroups: comp.dsp Subject: [SPECULATION] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Jun22.060429.2432@illinois.edu> Date: Wed, 22 Jun 1994 06:04:29 GMT Organization: University of Illinois Urbana-Champaign NNTP-Posting-Host: illinois.edu 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. 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? -- === Valeria Silva === Dept of Electrical Engineering, University of Illinois Urbana-Champaign "When every node is whole, the channel opens." From cnilsson@uu.net Wed Jun 22 16:07:29 1994 Path: ashpoly!bigsur!pacrim!jpgate!kamome!uu!cnilsson From: cnilsson@uu.net (Camila Nilsson) Newsgroups: comp.dsp Subject: Re: [SPECULATION] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Jun22.160729.4865@uu.net> Date: Wed, 22 Jun 1994 16:07:29 GMT References: <1994Jun22.060429.2432@illinois.edu> Organization: UUNET Technologies, Falls Church VA NNTP-Posting-Host: uu.net X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1994Jun22.060429.2432@illinois.edu>, vsilva@illinois.edu (Valeria Silva) writes: > A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips. > 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. -- Camila Nilsson "Hardware is temporary. The signal survives." Sun SparcStation 20 / System 7.5.1 From rtakahashi@illinois.edu Fri Jun 24 15:12:29 1994 Path: ashpoly!cascade!mxgate!coyoacan!illinois!rtakahashi From: rtakahashi@illinois.edu (Rodrigo Takahashi) Newsgroups: comp.dsp Subject: Re: [SPECULATION] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Jun24.151229.5997@illinois.edu> Date: Fri, 24 Jun 1994 15:12:29 GMT References: <1994Jun22.060429.2432@illinois.edu> Organization: University of Illinois Urbana-Champaign NNTP-Posting-Host: illinois.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1994Jun22.060429.2432@illinois.edu>, vsilva@illinois.edu (Valeria Silva) writes: > A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips. > 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. -- Rodrigo Takahashi -- University of Illinois Urbana-Champaign "Tape doesn't lie at 02:14. Ears do."