From sjohansson@earthlink.net Wed Sep 25 21:44:57 1996 Path: ashpoly!bigsur!pacrim!jpgate!kamome!earthlink!sjohansson From: sjohansson@earthlink.net (Sun-mi Johansson) Newsgroups: comp.dsp Subject: [FLAME] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Sep25.214457.8940@earthlink.net> Date: Wed, 25 Sep 1996 21:44:57 GMT Organization: EarthLink Network NNTP-Posting-Host: earthlink.net X-Newsreader: WinVN 0.99.5 Lines: 11 Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz. 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? -- Sun-mi Johansson *PLONK* filter active for trolls. Atari TT030 - NetBSD 1.0 From tmacdonald@pipeline.com Thu Sep 26 05:36:57 1996 Path: ashpoly!bigsur!pacrim!jpgate!kamome!pipeline!tmacdonald From: tmacdonald@pipeline.com (Thiago MacDonald) Newsgroups: comp.dsp Subject: Re: [FLAME] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Sep26.053657.9470@pipeline.com> Date: Thu, 26 Sep 1996 05:36:57 GMT References: <1996Sep25.214457.8940@earthlink.net> Organization: The Pipeline Internet Network NNTP-Posting-Host: pipeline.com X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1996Sep25.214457.8940@earthlink.net>, sjohansson@earthlink.net (Sun-mi Johansson) writes: > Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- === Thiago MacDonald === Dept of Electrical Engineering, The Pipeline Internet Network "In theory there is no difference between theory and practice." From bfournier@kth.se Fri Sep 27 02:32:57 1996 Path: ashpoly!cascade!mxgate!coyoacan!kth!bfournier From: bfournier@kth.se (Bruno Fournier) Newsgroups: comp.dsp Subject: Re: [FLAME] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Sep27.023257.5775@kth.se> Date: Fri, 27 Sep 1996 02:32:57 GMT References: <1996Sep25.214457.8940@earthlink.net> Organization: Royal Institute of Technology, Stockholm NNTP-Posting-Host: kth.se X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1996Sep25.214457.8940@earthlink.net>, sjohansson@earthlink.net (Sun-mi Johansson) writes: > Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz. > 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. -- Bruno Fournier Tape trading list upon request. SASE required for international mail.