From keriksson@kiae.su Fri Jun 23 14:50:19 1995 Path: ashpoly!cascade!transat!eunet-fr!teletel!kiae!keriksson From: keriksson@kiae.su (Karen Eriksson) Newsgroups: comp.dsp Subject: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Jun23.145019.2969@kiae.su> Date: Fri, 23 Jun 1995 14:50:19 GMT Organization: Kurchatov Institute of Atomic Energy, Moscow NNTP-Posting-Host: kiae.su X-Newsreader: Netscape 1.1N Lines: 11 A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips. A Kaiser-Bessel window with parameter beta = 8.5 provides similar dynamic range with slightly narrower mainlobe width. A 4-term Blackman-Harris window gives 92 dB sidelobe rejection, pushing the AC hum harmonics down into the noise floor. What sampling rates are people using for their vinyl rips? 44.1 kHz or 48 kHz DAT? -- Karen Eriksson *PLONK* filter active for trolls. Amiga 3000T - NetBSD 1.0 From dfischer@stanford.edu Sat Jun 24 23:10:19 1995 Path: ashpoly!cascade!mxgate!coyoacan!stanford!dfischer From: dfischer@stanford.edu (Dave Fischer) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Jun24.231019.4398@stanford.edu> Date: Sat, 24 Jun 1995 23:10:19 GMT References: <1995Jun23.145019.2969@kiae.su> Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1995Jun23.145019.2969@kiae.su>, keriksson@kiae.su (Karen Eriksson) writes: > A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips. > A Kaiser-Bessel window with parameter beta = 8.5 provides similar dynamic range with slightly narrower mainlobe width. 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. -- Dave Fischer US Robotics Courier V.34 @ 28,800 bps "The carrier frequency does not drift by accident."