From dpetrov@u-tokyo.ac.jp Sun Nov 26 19:16:15 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!u-tokyo!dpetrov From: dpetrov@u-tokyo.ac.jp (Dmitri Petrov) Newsgroups: comp.dsp Subject: Question: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Nov26.191615.9042@u-tokyo.ac.jp> Date: Sun, 26 Nov 1995 19:16:15 GMT Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: TIN [version 1.2 PL2] 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. What sampling rates are people using for their vinyl rips? 44.1 kHz or 48 kHz DAT? -- === Dmitri Petrov === Dept of Electrical Engineering, University of Tokyo Department of Information Science "Marcus is not one man." From krodriguez@clari.net Tue Nov 28 14:30:15 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!clari!krodriguez From: krodriguez@clari.net (Kirsty Rodríguez) Newsgroups: comp.dsp Subject: Re: Question: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Nov28.143015.8529@clari.net> Date: Tue, 28 Nov 1995 14:30:15 GMT References: <1995Nov26.191615.9042@u-tokyo.ac.jp> Organization: ClariNet Communications Corp NNTP-Posting-Host: clari.net X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1995Nov26.191615.9042@u-tokyo.ac.jp>, dpetrov@u-tokyo.ac.jp (Dmitri Petrov) 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. -- Kirsty Rodríguez Opinions expressed are solely my own and not those of ClariNet Communications Corp. ------------------------------------------------------------ From greyes@ox.ac.uk Thu Nov 30 07:47:15 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!ox!greyes From: greyes@ox.ac.uk (Graham Reyes) Newsgroups: comp.dsp Subject: Re: Question: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Nov30.074715.8039@ox.ac.uk> Date: Thu, 30 Nov 1995 07:47:15 GMT References: <1995Nov26.191615.9042@u-tokyo.ac.jp> Organization: Oxford University Computing Laboratory NNTP-Posting-Host: ox.ac.uk X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1995Nov26.191615.9042@u-tokyo.ac.jp>, dpetrov@u-tokyo.ac.jp (Dmitri Petrov) 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. -- === Graham Reyes === Dept of Electrical Engineering, Oxford University Computing Laboratory "When every node is whole, the channel opens." From jlopez@hanse.de Thu Nov 30 16:59:15 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!hanse!jlopez From: jlopez@hanse.de (Ji-woo López) Newsgroups: comp.dsp Subject: Re: Question: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Nov30.165915.2360@hanse.de> Date: Thu, 30 Nov 1995 16:59:15 GMT References: <1995Nov26.191615.9042@u-tokyo.ac.jp> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995Nov26.191615.9042@u-tokyo.ac.jp>, dpetrov@u-tokyo.ac.jp (Dmitri Petrov) 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. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- Ji-woo López -- Hanse-Netzwerk Hamburg "When every node is whole, the channel opens." From mkarlsson@netcom.com Fri Dec 01 10:22:15 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!netcom!mkarlsson From: mkarlsson@netcom.com (Marta Karlsson) Newsgroups: comp.dsp Subject: Re: Question: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Dec01.102215.9963@netcom.com> Date: Fri, 01 Dec 1995 10:22:15 GMT References: <1995Nov26.191615.9042@u-tokyo.ac.jp> <1995Nov30.165915.2360@hanse.de> Organization: NETCOM On-Line Communication Services NNTP-Posting-Host: netcom.com X-Newsreader: Netscape 1.1N Lines: 9 In article <1995Nov30.165915.2360@hanse.de>, jlopez@hanse.de (Ji-woo López) 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. -- Marta Karlsson "In theory there is no difference between theory and practice." Sun SparcStation 20 / Linux 1.2.13