From ljohansson@berkeley.edu Tue Mar 26 03:37:22 1996 Path: ashpoly!bigsur!pacrim!krgate!eunha!berkeley!ljohansson From: ljohansson@berkeley.edu (Lucia Johansson) Newsgroups: comp.dsp Subject: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Mar26.033722.2062@berkeley.edu> Date: Tue, 26 Mar 1996 03:37:22 GMT Organization: UC Berkeley Department of EECS NNTP-Posting-Host: berkeley.edu X-Newsreader: Netscape 1.1N Lines: 10 A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips. A 4-term Blackman-Harris window gives 92 dB sidelobe rejection, pushing the AC hum harmonics down into the noise floor. 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? -- Lucia Johansson Tape trading list upon request. SASE required for international mail. From hduarte@delphi.com Wed Mar 27 18:40:22 1996 Path: ashpoly!cascade!transat!eunet-fr!teletel!delphi!hduarte From: hduarte@delphi.com (Heather Duarte) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Mar27.184022.5372@delphi.com> Date: Wed, 27 Mar 1996 18:40:22 GMT References: <1996Mar26.033722.2062@berkeley.edu> Organization: Delphi Internet Services NNTP-Posting-Host: delphi.com X-Newsreader: Netscape 1.1N Lines: 9 In article <1996Mar26.033722.2062@berkeley.edu>, ljohansson@berkeley.edu (Lucia Johansson) writes: > A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips. 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. -- Heather Duarte "Hardware is temporary. The signal survives." Macintosh IIfx / TOS 4.04