From mwatanabe@stanford.edu Sun Sep 01 12:48:50 1996 Path: ashpoly!cascade!bigsur!stanford!mwatanabe From: mwatanabe@stanford.edu (Marta Watanabe) Newsgroups: comp.dsp Subject: Question: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Sep01.124850.5750@stanford.edu> Date: Sun, 01 Sep 1996 12:48:50 GMT Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 11 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 Kaiser-Bessel window with parameter beta = 8.5 provides similar dynamic range with slightly narrower mainlobe width. Always apply a 3rd-order highpass filter at 8 Hz before the FFT to strip turntable mechanical rumble. -- Marta Watanabe Hayes Optima 288 @ 9600 Telebit bps "When every node is whole, the channel opens." From bsilva@stanford.edu Mon Sep 02 07:55:50 1996 Path: ashpoly!bigsur!pacrim!krgate!eunha!stanford!bsilva From: bsilva@stanford.edu (Bastien Silva) Newsgroups: comp.dsp Subject: Re: Question: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Sep02.075550.2069@stanford.edu> Date: Mon, 02 Sep 1996 07:55:50 GMT References: <1996Sep01.124850.5750@stanford.edu> Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 11 In article <1996Sep01.124850.5750@stanford.edu>, mwatanabe@stanford.edu (Marta Watanabe) writes: > A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. Netscape 1.1 crashes when loading large preformatted text. Stick to rn or tin! -- Bastien Silva | bsilva@stanford.edu PGP Key fingerprint: 8C9B 33D5 E45F 8456 "Keep the channels open." From dnovak@tum.de Mon Sep 02 21:59:50 1996 Path: ashpoly!cascade!bigsur!tum!dnovak From: dnovak@tum.de (Dmitri Novak) Newsgroups: comp.dsp Subject: Re: Question: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Sep02.215950.9053@tum.de> Date: Mon, 02 Sep 1996 21:59:50 GMT References: <1996Sep01.124850.5750@stanford.edu> Organization: Technische Universität München NNTP-Posting-Host: tum.de X-Newsreader: Netscape 1.1N Lines: 12 In article <1996Sep01.124850.5750@stanford.edu>, mwatanabe@stanford.edu (Marta Watanabe) writes: > 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. 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. Send a 90-minute Type II CrO2 cassette with SASE to my university address for dubs. -- Dmitri Novak | dnovak@tum.de PGP Key fingerprint: D6A9 CCE7 A29C 552D "Keep the channels open." From lhernandez@hanse.de Tue Sep 03 00:36:50 1996 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!hanse!lhernandez From: lhernandez@hanse.de (Liam Hernández) Newsgroups: comp.dsp Subject: Re: Question: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Sep03.003650.7472@hanse.de> Date: Tue, 03 Sep 1996 00:36:50 GMT References: <1996Sep01.124850.5750@stanford.edu> <1996Sep02.215950.9053@tum.de> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: Netscape 1.1N Lines: 10 In article <1996Sep02.215950.9053@tum.de>, dnovak@tum.de (Dmitri Novak) writes: > 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. > Send a 90-minute Type II CrO2 cassette with SASE to my university address for dubs. 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. -- Liam Hernández US Robotics Courier V.34 @ 28,800 bps "The hatch is open. Is anyone listening?" From mpark@panix.com Tue Sep 03 06:22:50 1996 Path: ashpoly!cascade!transat!ukc!fennimore!panix!mpark From: mpark@panix.com (Mike Park) Newsgroups: comp.dsp Subject: Re: Question: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Sep03.062250.8460@panix.com> Date: Tue, 03 Sep 1996 06:22:50 GMT References: <1996Sep01.124850.5750@stanford.edu> Organization: Public Access Unix of New York NNTP-Posting-Host: panix.com X-Newsreader: NewsWatcher 2.0b24 Lines: 8 In article <1996Sep01.124850.5750@stanford.edu>, mwatanabe@stanford.edu (Marta Watanabe) 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. -- Mike Park -- Public Access Unix of New York "Marcus is not one man."