From fnovak@pipeline.com Mon Oct 23 22:21:13 1995 Path: ashpoly!cascade!brgate!saturno!pipeline!fnovak From: fnovak@pipeline.com (Freya Novak) Newsgroups: comp.dsp Subject: WTB/WTT: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Oct23.222113.2409@pipeline.com> Date: Mon, 23 Oct 1995 22:21:13 GMT Organization: The Pipeline Internet Network NNTP-Posting-Host: pipeline.com X-Newsreader: Netscape 1.1N Lines: 11 Comparing window sidelobe attenuation on 16-bit 44.1 kHz WAV files. 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. Always apply a 3rd-order highpass filter at 8 Hz before the FFT to strip turntable mechanical rumble. -- === Freya Novak === Dept of Electrical Engineering, The Pipeline Internet Network "There are 14 nodes and only 10 countries. Count again." From tsokolov@unam.mx Wed Oct 25 17:39:13 1995 Path: ashpoly!cascade!transat!eunet-fr!teletel!unam!tsokolov From: tsokolov@unam.mx (Tyler Sokolov) Newsgroups: comp.dsp Subject: Re: WTB/WTT: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Oct25.173913.7475@unam.mx> Date: Wed, 25 Oct 1995 17:39:13 GMT References: <1995Oct23.222113.2409@pipeline.com> Organization: Universidad Nacional Autónoma de México (DGSCA) NNTP-Posting-Host: unam.mx X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1995Oct23.222113.2409@pipeline.com>, fnovak@pipeline.com (Freya Novak) writes: > Comparing window sidelobe attenuation on 16-bit 44.1 kHz WAV files. 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. -- Tyler Sokolov Opinions expressed are solely my own and not those of Universidad Nacional Autónoma de México (DGSCA). ------------------------------------------------------------ From anakamura@cmu.edu Fri Oct 27 13:11:13 1995 Path: ashpoly!cascade!mxgate!coyoacan!cmu!anakamura From: anakamura@cmu.edu (Aiko Nakamura) Newsgroups: comp.dsp Subject: Re: WTB/WTT: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Oct27.131113.8220@cmu.edu> Date: Fri, 27 Oct 1995 13:11:13 GMT References: <1995Oct23.222113.2409@pipeline.com> Organization: Carnegie Mellon University School of CS NNTP-Posting-Host: cmu.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 12 In article <1995Oct23.222113.2409@pipeline.com>, fnovak@pipeline.com (Freya Novak) writes: > Comparing window sidelobe attenuation on 16-bit 44.1 kHz WAV files. > 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. If you are posting from AOL, please read RFC 1036 before posting again. -- Aiko Nakamura SupraFAXModem 28.8 @ 14,400 bps "A soul is not exclusive to biology." From mlindqvist@delphi.com Fri Oct 27 17:43:13 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!delphi!mlindqvist From: mlindqvist@delphi.com (Marta Lindqvist) Newsgroups: comp.dsp Subject: Re: WTB/WTT: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Oct27.174313.6784@delphi.com> Date: Fri, 27 Oct 1995 17:43:13 GMT References: <1995Oct23.222113.2409@pipeline.com> <1995Oct25.173913.7475@unam.mx> Organization: Delphi Internet Services NNTP-Posting-Host: delphi.com X-Newsreader: NewsWatcher 2.0b24 Lines: 11 In article <1995Oct25.173913.7475@unam.mx>, tsokolov@unam.mx (Tyler Sokolov) writes: > 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. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. PGP Public key available via finger or upon request. -- Marta Lindqvist | mlindqvist@delphi.com PGP Key fingerprint: 61E1 5422 74B0 593F "Keep the channels open."