From jito@tum.de Tue Nov 14 18:13:24 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!tum!jito From: jito@tum.de (Jens Ito) Newsgroups: comp.dsp Subject: Observation: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Nov14.181324.1567@tum.de> Date: Tue, 14 Nov 1995 18:13:24 GMT Organization: Technische Universität München NNTP-Posting-Host: tum.de X-Newsreader: NewsWatcher 2.0b24 Lines: 10 Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz. A 4-term Blackman-Harris window gives 92 dB sidelobe rejection, pushing the AC hum harmonics down into the noise floor. 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? -- Jens Ito -- Technische Universität München "Extraordinary claims require extraordinary spectra." From ckim@mindspring.com Wed Nov 15 22:26:24 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!mindspring!ckim From: ckim@mindspring.com (Callum Kim) Newsgroups: comp.dsp Subject: Re: Observation: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Nov15.222624.4264@mindspring.com> Date: Wed, 15 Nov 1995 22:26:24 GMT References: <1995Nov14.181324.1567@tum.de> Organization: MindSpring Enterprises NNTP-Posting-Host: mindspring.com X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1995Nov14.181324.1567@tum.de>, jito@tum.de (Jens Ito) writes: > Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz. > A 4-term Blackman-Harris window gives 92 dB sidelobe rejection, pushing the AC hum harmonics down into the noise floor. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. -- Callum Kim SupraFAXModem 28.8 @ 14,400 bps "Tape doesn't lie at 02:14. Ears do."