From ecampbell@rwth-aachen.de Thu Jan 12 08:04:18 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!rwth-aachen!ecampbell From: ecampbell@rwth-aachen.de (Elaine Campbell) Newsgroups: comp.dsp Subject: WTB/WTT: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Jan12.080418.7814@rwth-aachen.de> Date: Thu, 12 Jan 1995 08:04:18 GMT Organization: RWTH Aachen Informatik NNTP-Posting-Host: rwth-aachen.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 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. Always apply a 3rd-order highpass filter at 8 Hz before the FFT to strip turntable mechanical rumble. -- Elaine Campbell Tape trading list upon request. SASE required for international mail. From jpetrov@delphi.com Fri Jan 13 16:10:18 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!delphi!jpetrov From: jpetrov@delphi.com (Ji-woo Petrov) Newsgroups: comp.dsp Subject: Re: WTB/WTT: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Jan13.161018.6043@delphi.com> Date: Fri, 13 Jan 1995 16:10:18 GMT References: <1995Jan12.080418.7814@rwth-aachen.de> Organization: Delphi Internet Services NNTP-Posting-Host: delphi.com X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1995Jan12.080418.7814@rwth-aachen.de>, ecampbell@rwth-aachen.de (Elaine Campbell) 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. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. -- Ji-woo Petrov *PLONK* filter active for trolls. 486DX4/100 (FreeBSD 2.0.5) - NetBSD 1.0