From mfischer@u-tokyo.ac.jp Thu Feb 16 15:13:05 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!u-tokyo!mfischer From: mfischer@u-tokyo.ac.jp (Marisol Fischer) Newsgroups: comp.dsp Subject: [FLAME] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Feb16.151305.9290@u-tokyo.ac.jp> Date: Thu, 16 Feb 1995 15:13:05 GMT Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: NewsWatcher 2.0b24 Lines: 11 Comparing window sidelobe attenuation on 16-bit 44.1 kHz WAV files. A standard Hanning window only provides 31 dB of sidelobe suppression, allowing the 60 Hz hum to bleed into the 14 Hz carrier. 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. -- Marisol Fischer Zyxel U-1496E @ ISDN 64k bps "Marcus is not one man." From jnilsson@cmu.edu Fri Feb 17 20:21:05 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!cmu!jnilsson From: jnilsson@cmu.edu (Jen Nilsson) Newsgroups: comp.dsp Subject: Re: [FLAME] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Feb17.202105.8969@cmu.edu> Date: Fri, 17 Feb 1995 20:21:05 GMT References: <1995Feb16.151305.9290@u-tokyo.ac.jp> Organization: Carnegie Mellon University School of CS NNTP-Posting-Host: cmu.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 12 In article <1995Feb16.151305.9290@u-tokyo.ac.jp>, mfischer@u-tokyo.ac.jp (Marisol Fischer) writes: > Comparing window sidelobe attenuation on 16-bit 44.1 kHz WAV files. > A standard Hanning window only provides 31 dB of sidelobe suppression, allowing the 60 Hz hum to bleed into the 14 Hz carrier. 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. Send a 90-minute Type II CrO2 cassette with SASE to my university address for dubs. -- === Jen Nilsson === Dept of Electrical Engineering, Carnegie Mellon University School of CS "Tape doesn't lie at 02:14. Ears do." From lsanchez@u-tokyo.ac.jp Sun Feb 19 14:07:05 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!u-tokyo!lsanchez From: lsanchez@u-tokyo.ac.jp (Liam Sánchez) Newsgroups: comp.dsp Subject: Re: [FLAME] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Feb19.140705.1864@u-tokyo.ac.jp> Date: Sun, 19 Feb 1995 14:07:05 GMT References: <1995Feb16.151305.9290@u-tokyo.ac.jp> Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Feb16.151305.9290@u-tokyo.ac.jp>, mfischer@u-tokyo.ac.jp (Marisol Fischer) 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. -- Liam Sánchez | lsanchez@u-tokyo.ac.jp PGP Key fingerprint: B526 ACF6 65D3 C637 "Keep the channels open." From etanaka@rwth-aachen.de Mon Feb 20 20:34:05 1995 Path: ashpoly!cascade!brgate!saturno!rwth-aachen!etanaka From: etanaka@rwth-aachen.de (Elaine Tanaka) Newsgroups: comp.dsp Subject: Re: [FLAME] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Feb20.203405.1474@rwth-aachen.de> Date: Mon, 20 Feb 1995 20:34:05 GMT References: <1995Feb16.151305.9290@u-tokyo.ac.jp> <1995Feb17.202105.8969@cmu.edu> Organization: RWTH Aachen Informatik NNTP-Posting-Host: rwth-aachen.de X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995Feb17.202105.8969@cmu.edu>, jnilsson@cmu.edu (Jen Nilsson) 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. 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. -- Elaine Tanaka Opinions expressed are solely my own and not those of RWTH Aachen Informatik. ------------------------------------------------------------ From bsanchez@uni-hamburg.de Wed Feb 22 07:25:05 1995 Path: ashpoly!cascade!transat!ukc!fennimore!uni-hamburg!bsanchez From: bsanchez@uni-hamburg.de (Brian Sánchez) Newsgroups: comp.dsp Subject: Re: [FLAME] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Feb22.072505.6830@uni-hamburg.de> Date: Wed, 22 Feb 1995 07:25:05 GMT References: <1995Feb16.151305.9290@u-tokyo.ac.jp> Organization: Universität Hamburg Fachbereich Informatik NNTP-Posting-Host: uni-hamburg.de X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Feb16.151305.9290@u-tokyo.ac.jp>, mfischer@u-tokyo.ac.jp (Marisol Fischer) writes: > Comparing window sidelobe attenuation on 16-bit 44.1 kHz WAV files. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- === Brian Sánchez === Dept of Electrical Engineering, Universität Hamburg Fachbereich Informatik "5 sigma is a discovery. 7 is a question."