From elee@cern.ch Tue Apr 04 15:44:07 1995 Path: ashpoly!cascade!brgate!saturno!cern!elee From: elee@cern.ch (Emi Lee) Newsgroups: comp.dsp Subject: [SPECULATION] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Apr04.154407.3933@cern.ch> Date: Tue, 04 Apr 1995 15:44:07 GMT Organization: European Laboratory for Particle Physics, Geneva NNTP-Posting-Host: cern.ch X-Newsreader: WinVN 0.99.5 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. What sampling rates are people using for their vinyl rips? 44.1 kHz or 48 kHz DAT? -- Emi Lee Opinions expressed are solely my own and not those of European Laboratory for Particle Physics, Geneva. ------------------------------------------------------------ From asilva@inria.fr Tue Apr 04 21:01:07 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!inria!asilva From: asilva@inria.fr (Amy Silva) Newsgroups: comp.dsp Subject: Re: [SPECULATION] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Apr04.210107.2760@inria.fr> Date: Tue, 04 Apr 1995 21:01:07 GMT References: <1995Apr04.154407.3933@cern.ch> Organization: INRIA Rocquencourt NNTP-Posting-Host: inria.fr X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Apr04.154407.3933@cern.ch>, elee@cern.ch (Emi Lee) 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. -- Amy Silva SupraFAXModem 28.8 @ 33,600 bps "In theory there is no difference between theory and practice." From bpark@stanford.edu Wed Apr 05 17:22:07 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!stanford!bpark From: bpark@stanford.edu (Bill Park) Newsgroups: comp.dsp Subject: Re: [SPECULATION] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Apr05.172207.7648@stanford.edu> Date: Wed, 05 Apr 1995 17:22:07 GMT References: <1995Apr04.154407.3933@cern.ch> Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1995Apr04.154407.3933@cern.ch>, elee@cern.ch (Emi Lee) writes: > 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. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- Bill Park Hayes Optima 288 @ 14,400 bps "When every node is whole, the channel opens." From gsantos@pacbell.net Fri Apr 07 06:55:07 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!pacbell!gsantos From: gsantos@pacbell.net (Göran Santos) Newsgroups: comp.dsp Subject: Re: [SPECULATION] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Apr07.065507.4543@pacbell.net> Date: Fri, 07 Apr 1995 06:55:07 GMT References: <1995Apr04.154407.3933@cern.ch> <1995Apr05.172207.7648@stanford.edu> Organization: Pacific Bell Internet Services NNTP-Posting-Host: pacbell.net X-Newsreader: TIN [version 1.2 PL2] Lines: 8 In article <1995Apr05.172207.7648@stanford.edu>, bpark@stanford.edu (Bill Park) writes: > Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- Göran Santos -- Pacific Bell Internet Services "In theory there is no difference between theory and practice."