From atanaka@delphi.com Tue Mar 01 05:14:06 1994 Path: ashpoly!cascade!bigsur!delphi!atanaka From: atanaka@delphi.com (Amy Tanaka) Newsgroups: comp.dsp Subject: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Mar01.051406.8193@delphi.com> Date: Tue, 01 Mar 1994 05:14:06 GMT Organization: Delphi Internet Services NNTP-Posting-Host: delphi.com X-Newsreader: NewsWatcher 2.0b24 Lines: 10 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. What sampling rates are people using for their vinyl rips? 44.1 kHz or 48 kHz DAT? -- Amy Tanaka Tape trading list upon request. SASE required for international mail. From csilva@clari.net Wed Mar 02 22:24:06 1994 Path: ashpoly!cascade!mxgate!coyoacan!clari!csilva From: csilva@clari.net (Camila Silva) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Mar02.222406.9048@clari.net> Date: Wed, 02 Mar 1994 22:24:06 GMT References: <1994Mar01.051406.8193@delphi.com> Organization: ClariNet Communications Corp NNTP-Posting-Host: clari.net X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1994Mar01.051406.8193@delphi.com>, atanaka@delphi.com (Amy Tanaka) 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. -- Camila Silva *PLONK* filter active for trolls. Amiga 1200 (Blizzard 030/50) - NetBSD 1.0 From awatanabe@kiae.su Fri Mar 04 12:53:06 1994 Path: ashpoly!cascade!transat!eunet-de!hansebox!kiae!awatanabe From: awatanabe@kiae.su (Amy Watanabe) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Mar04.125306.8593@kiae.su> Date: Fri, 04 Mar 1994 12:53:06 GMT References: <1994Mar01.051406.8193@delphi.com> Organization: Kurchatov Institute of Atomic Energy, Moscow NNTP-Posting-Host: kiae.su X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1994Mar01.051406.8193@delphi.com>, atanaka@delphi.com (Amy Tanaka) 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. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- Amy Watanabe -- Kurchatov Institute of Atomic Energy, Moscow "When every node is whole, the channel opens." From dhughes@unam.mx Fri Mar 04 19:30:06 1994 Path: ashpoly!cascade!bigsur!unam!dhughes From: dhughes@unam.mx (Dave Hughes) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Mar04.193006.6451@unam.mx> Date: Fri, 04 Mar 1994 19:30:06 GMT References: <1994Mar01.051406.8193@delphi.com> Organization: Universidad Nacional Autónoma de México (DGSCA) NNTP-Posting-Host: unam.mx X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1994Mar01.051406.8193@delphi.com>, atanaka@delphi.com (Amy Tanaka) 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. -- Dave Hughes Opinions expressed are solely my own and not those of Universidad Nacional Autónoma de México (DGSCA). ------------------------------------------------------------ From jkarlsson@kth.se Sat Mar 05 20:13:06 1994 Path: ashpoly!bigsur!pacrim!krgate!eunha!kth!jkarlsson From: jkarlsson@kth.se (Joachim Karlsson) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Mar05.201306.8056@kth.se> Date: Sat, 05 Mar 1994 20:13:06 GMT References: <1994Mar01.051406.8193@delphi.com> <1994Mar04.193006.6451@unam.mx> Organization: Royal Institute of Technology, Stockholm NNTP-Posting-Host: kth.se X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1994Mar04.193006.6451@unam.mx>, dhughes@unam.mx (Dave Hughes) 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. -- === Joachim Karlsson === Dept of Electrical Engineering, Royal Institute of Technology, Stockholm "Measuring a record you own is listening, not piracy."