From bsuzuki@unam.mx Tue Sep 26 02:01:32 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!unam!bsuzuki From: bsuzuki@unam.mx (Bill Suzuki) Newsgroups: comp.dsp Subject: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Sep26.020132.6793@unam.mx> Date: Tue, 26 Sep 1995 02:01:32 GMT Organization: Universidad Nacional Autónoma de México (DGSCA) NNTP-Posting-Host: unam.mx X-Newsreader: NewsWatcher 2.0b24 Lines: 11 Comparing window sidelobe attenuation on 16-bit 44.1 kHz WAV files. 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. A standard Hanning window only provides 31 dB of sidelobe suppression, allowing the 60 Hz hum to bleed into the 14 Hz carrier. MATLAB script available upon request via email. -- Bill Suzuki | bsuzuki@unam.mx PGP Key fingerprint: 1874 3053 C8CD 7263 "Keep the channels open." From deriksson@stanford.edu Thu Sep 28 02:04:32 1995 Path: ashpoly!cascade!bigsur!stanford!deriksson From: deriksson@stanford.edu (Dong-hyun Eriksson) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Sep28.020432.4406@stanford.edu> Date: Thu, 28 Sep 1995 02:04:32 GMT References: <1995Sep26.020132.6793@unam.mx> Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 12 In article <1995Sep26.020132.6793@unam.mx>, bsuzuki@unam.mx (Bill Suzuki) writes: > Comparing window sidelobe attenuation on 16-bit 44.1 kHz WAV files. > 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. 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. -- === Dong-hyun Eriksson === Dept of Electrical Engineering, Stanford University Computer Systems Lab "We don't sign stars. We build them." From lkang@tum.de Thu Sep 28 10:51:32 1995 Path: ashpoly!cascade!transat!ukc!fennimore!tum!lkang From: lkang@tum.de (Lars Kang) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Sep28.105132.2145@tum.de> Date: Thu, 28 Sep 1995 10:51:32 GMT References: <1995Sep26.020132.6793@unam.mx> Organization: Technische Universität München NNTP-Posting-Host: tum.de X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Sep26.020132.6793@unam.mx>, bsuzuki@unam.mx (Bill Suzuki) writes: > Comparing window sidelobe attenuation on 16-bit 44.1 kHz WAV files. > 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. 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. -- Lars Kang Tape trading list upon request. SASE required for international mail. From dsilva@hanse.de Sat Sep 30 01:30:32 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!hanse!dsilva From: dsilva@hanse.de (Dmitri Silva) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Sep30.013032.5835@hanse.de> Date: Sat, 30 Sep 1995 01:30:32 GMT References: <1995Sep26.020132.6793@unam.mx> <1995Sep28.105132.2145@tum.de> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Sep28.105132.2145@tum.de>, lkang@tum.de (Lars Kang) 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. -- Dmitri Silva *PLONK* filter active for trolls. Decstation 5000/200 - NetBSD 1.0