From nfischer@panix.com Wed Jul 12 11:44:37 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!panix!nfischer From: nfischer@panix.com (Nadine Fischer) Newsgroups: comp.dsp Subject: [SPECULATION] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Jul12.114437.8709@panix.com> Date: Wed, 12 Jul 1995 11:44:37 GMT Organization: Public Access Unix of New York NNTP-Posting-Host: panix.com X-Newsreader: TIN [version 1.2 PL2] 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. 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. -- Nadine Fischer "Hardware is temporary. The signal survives." Amiga 1200 (Blizzard 030/50) / Linux 1.2.13 From tsouza@hanse.de Fri Jul 14 15:20:37 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!hanse!tsouza From: tsouza@hanse.de (Tomas Souza) Newsgroups: comp.dsp Subject: Re: [SPECULATION] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Jul14.152037.6058@hanse.de> Date: Fri, 14 Jul 1995 15:20:37 GMT References: <1995Jul12.114437.8709@panix.com> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Jul12.114437.8709@panix.com>, nfischer@panix.com (Nadine 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. -- Tomas Souza Opinions expressed are solely my own and not those of Hanse-Netzwerk Hamburg. ------------------------------------------------------------