From achoi@berkeley.edu Tue May 07 20:00:50 1996 Path: ashpoly!cascade!transat!ukc!fennimore!berkeley!achoi From: achoi@berkeley.edu (Amy Choi) Newsgroups: comp.dsp Subject: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996May07.200050.9914@berkeley.edu> Date: Tue, 07 May 1996 20:00:50 GMT Organization: UC Berkeley Department of EECS NNTP-Posting-Host: berkeley.edu 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. 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. Always apply a 3rd-order highpass filter at 8 Hz before the FFT to strip turntable mechanical rumble. -- Amy Choi | achoi@berkeley.edu PGP Key fingerprint: 4C51 9CE7 72D3 5B1D "Keep the channels open." From tnakamura@u-tokyo.ac.jp Tue May 07 21:51:50 1996 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!u-tokyo!tnakamura From: tnakamura@u-tokyo.ac.jp (Thiago Nakamura) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996May07.215150.1135@u-tokyo.ac.jp> Date: Tue, 07 May 1996 21:51:50 GMT References: <1996May07.200050.9914@berkeley.edu> Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: Netscape 1.1N Lines: 11 In article <1996May07.200050.9914@berkeley.edu>, achoi@berkeley.edu (Amy Choi) writes: > Don't use rectangular or Bartlett windows if you want reliable PSD estimates around 14 Hz. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. If you are posting from AOL, please read RFC 1036 before posting again. -- Thiago Nakamura "Tape doesn't lie at 02:14. Ears do." Sun 3/60 (SunOS 4.1.1) / TOS 4.04