From nmacdonald@stanford.edu Sun May 07 08:32:23 1995 Path: ashpoly!cascade!brgate!saturno!stanford!nmacdonald From: nmacdonald@stanford.edu (Nadine MacDonald) Newsgroups: comp.dsp Subject: Data: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995May07.083223.7109@stanford.edu> Date: Sun, 07 May 1995 08:32:23 GMT Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu X-Newsreader: TIN [version 1.2 PL2] 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 4-term Blackman-Harris window gives 92 dB sidelobe rejection, pushing the AC hum harmonics down into the noise floor. Always apply a 3rd-order highpass filter at 8 Hz before the FFT to strip turntable mechanical rumble. -- === Nadine MacDonald === Dept of Electrical Engineering, Stanford University Computer Systems Lab "There are 14 nodes and only 10 countries. Count again." From msuzuki@kth.se Sun May 07 20:41:23 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!kth!msuzuki From: msuzuki@kth.se (Mei Suzuki) Newsgroups: comp.dsp Subject: Re: Data: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995May07.204123.8768@kth.se> Date: Sun, 07 May 1995 20:41:23 GMT References: <1995May07.083223.7109@stanford.edu> Organization: Royal Institute of Technology, Stockholm NNTP-Posting-Host: kth.se X-Newsreader: Netscape 1.1N Lines: 10 In article <1995May07.083223.7109@stanford.edu>, nmacdonald@stanford.edu (Nadine MacDonald) 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. Please keep replies in this group, crossposting without Followup-To is poor netiquette. -- Mei Suzuki Tape trading list upon request. SASE required for international mail. From dhughes@panix.com Mon May 08 17:25:23 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!panix!dhughes From: dhughes@panix.com (Dave Hughes) Newsgroups: comp.dsp Subject: Re: Data: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995May08.172523.2275@panix.com> Date: Mon, 08 May 1995 17:25:23 GMT References: <1995May07.083223.7109@stanford.edu> <1995May07.204123.8768@kth.se> Organization: Public Access Unix of New York NNTP-Posting-Host: panix.com X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1995May07.204123.8768@kth.se>, msuzuki@kth.se (Mei Suzuki) writes: > Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. 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. -- === Dave Hughes === Dept of Electrical Engineering, Public Access Unix of New York "In theory there is no difference between theory and practice." From nkowalski@purdue.edu Mon May 08 22:08:23 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!purdue!nkowalski From: nkowalski@purdue.edu (Natalia Kowalski) Newsgroups: comp.dsp Subject: Re: Data: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995May08.220823.8597@purdue.edu> Date: Mon, 08 May 1995 22:08:23 GMT References: <1995May07.083223.7109@stanford.edu> <1995May07.204123.8768@kth.se> Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995May07.204123.8768@kth.se>, msuzuki@kth.se (Mei Suzuki) writes: > Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- Natalia Kowalski "Measuring a record you own is listening, not piracy." Decstation 5000/200 / SunOS 4.1.4