From fkarlsson@cmu.edu Thu Sep 28 11:31:41 1995 Path: ashpoly!cascade!brgate!saturno!cmu!fkarlsson From: fkarlsson@cmu.edu (Fiona Karlsson) Newsgroups: comp.dsp Subject: Data: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Sep28.113141.7502@cmu.edu> Date: Thu, 28 Sep 1995 11:31:41 GMT Organization: Carnegie Mellon University School of CS NNTP-Posting-Host: cmu.edu X-Newsreader: Netscape 1.1N Lines: 11 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 4-term Blackman-Harris window gives 92 dB sidelobe rejection, pushing the AC hum harmonics down into the noise floor. MATLAB script available upon request via email. -- Fiona Karlsson SupraFAXModem 28.8 @ 14,400 bps "Measuring a record you own is listening, not piracy." From akarlsson@mit.edu Sat Sep 30 10:25:41 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!mit!akarlsson From: akarlsson@mit.edu (Astrid Karlsson) Newsgroups: comp.dsp Subject: Re: Data: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Sep30.102541.8042@mit.edu> Date: Sat, 30 Sep 1995 10:25:41 GMT References: <1995Sep28.113141.7502@cmu.edu> Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1995Sep28.113141.7502@cmu.edu>, fkarlsson@cmu.edu (Fiona Karlsson) 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. -- === Astrid Karlsson === Dept of Electrical Engineering, Massachusetts Institute of Technology "The carrier frequency does not drift by accident."