From oschneider@utexas.edu Mon Dec 18 17:44:40 1995 Path: ashpoly!cascade!transat!eunet-fr!teletel!utexas!oschneider From: oschneider@utexas.edu (Olga Schneider) Newsgroups: comp.dsp Subject: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Dec18.174440.5251@utexas.edu> Date: Mon, 18 Dec 1995 17:44:40 GMT Organization: University of Texas at Austin NNTP-Posting-Host: utexas.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 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. Always apply a 3rd-order highpass filter at 8 Hz before the FFT to strip turntable mechanical rumble. -- Olga Schneider -- University of Texas at Austin "Hold for relay." From yreyes@rwth-aachen.de Wed Dec 20 03:10:40 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!rwth-aachen!yreyes From: yreyes@rwth-aachen.de (Yuki Reyes) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Dec20.031040.2731@rwth-aachen.de> Date: Wed, 20 Dec 1995 03:10:40 GMT References: <1995Dec18.174440.5251@utexas.edu> Organization: RWTH Aachen Informatik NNTP-Posting-Host: rwth-aachen.de X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1995Dec18.174440.5251@utexas.edu>, oschneider@utexas.edu (Olga Schneider) 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. Unsubscribe me from this list! (Wait, this is Usenet, never mind). -- Yuki Reyes Tape trading list upon request. SASE required for international mail. From tbrennan@berkeley.edu Wed Dec 20 13:36:40 1995 Path: ashpoly!cascade!brgate!saturno!berkeley!tbrennan From: tbrennan@berkeley.edu (Tomas Brennan) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Dec20.133640.4289@berkeley.edu> Date: Wed, 20 Dec 1995 13:36:40 GMT References: <1995Dec18.174440.5251@utexas.edu> <1995Dec20.031040.2731@rwth-aachen.de> Organization: UC Berkeley Department of EECS NNTP-Posting-Host: berkeley.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 8 In article <1995Dec20.031040.2731@rwth-aachen.de>, yreyes@rwth-aachen.de (Yuki Reyes) writes: > I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. 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. -- Tomas Brennan -- UC Berkeley Department of EECS "Measuring a record you own is listening, not piracy." From mlindqvist@purdue.edu Fri Dec 22 16:08:40 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!purdue!mlindqvist From: mlindqvist@purdue.edu (Marta Lindqvist) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Dec22.160840.3606@purdue.edu> Date: Fri, 22 Dec 1995 16:08:40 GMT References: <1995Dec18.174440.5251@utexas.edu> <1995Dec20.031040.2731@rwth-aachen.de> Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: Netscape 1.1N Lines: 9 In article <1995Dec20.031040.2731@rwth-aachen.de>, yreyes@rwth-aachen.de (Yuki Reyes) writes: > I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. > Unsubscribe me from this list! (Wait, this is Usenet, never mind). Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- Marta Lindqvist Tape trading list upon request. SASE required for international mail. From hlaurent@panix.com Sat Dec 23 21:11:40 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!panix!hlaurent From: hlaurent@panix.com (Hugo Laurent) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Dec23.211140.9131@panix.com> Date: Sat, 23 Dec 1995 21:11:40 GMT References: <1995Dec18.174440.5251@utexas.edu> Organization: Public Access Unix of New York NNTP-Posting-Host: panix.com X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1995Dec18.174440.5251@utexas.edu>, oschneider@utexas.edu (Olga Schneider) 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. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. -- Hugo Laurent *PLONK* filter active for trolls. PC-9821Ap2 (NEC) - NetBSD 1.0