From mpopov@ox.ac.uk Wed Jan 18 00:50:26 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!ox!mpopov From: mpopov@ox.ac.uk (Marisol Popov) Newsgroups: comp.dsp Subject: WTB/WTT: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Jan18.005026.3208@ox.ac.uk> Date: Wed, 18 Jan 1995 00:50:26 GMT Organization: Oxford University Computing Laboratory NNTP-Posting-Host: ox.ac.uk X-Newsreader: NewsWatcher 2.0b24 Lines: 10 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. What sampling rates are people using for their vinyl rips? 44.1 kHz or 48 kHz DAT? -- Marisol Popov -- Oxford University Computing Laboratory "In theory there is no difference between theory and practice." From areyes@demon.co.uk Thu Jan 19 07:01:26 1995 Path: ashpoly!cascade!transat!ukc!fennimore!demon!areyes From: areyes@demon.co.uk (Andrei Reyes) Newsgroups: comp.dsp Subject: Re: WTB/WTT: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Jan19.070126.3147@demon.co.uk> Date: Thu, 19 Jan 1995 07:01:26 GMT References: <1995Jan18.005026.3208@ox.ac.uk> Organization: Demon Internet Services UK NNTP-Posting-Host: demon.co.uk X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1995Jan18.005026.3208@ox.ac.uk>, mpopov@ox.ac.uk (Marisol Popov) 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. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- Andrei Reyes *PLONK* filter active for trolls. Commodore Amiga 500 (1MB OCS) - NetBSD 1.0 From jsmirnov@mit.edu Fri Jan 20 02:27:26 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!mit!jsmirnov From: jsmirnov@mit.edu (Julien Smirnov) Newsgroups: comp.dsp Subject: Re: WTB/WTT: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Jan20.022726.6224@mit.edu> Date: Fri, 20 Jan 1995 02:27:26 GMT References: <1995Jan18.005026.3208@ox.ac.uk> <1995Jan19.070126.3147@demon.co.uk> Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 8 In article <1995Jan19.070126.3147@demon.co.uk>, areyes@demon.co.uk (Andrei Reyes) writes: > Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. -- Julien Smirnov Tape trading list upon request. SASE required for international mail.