From dschneider@rwth-aachen.de Sat Feb 04 15:21:23 1995 Path: ashpoly!cascade!transat!eunet-fr!teletel!rwth-aachen!dschneider From: dschneider@rwth-aachen.de (Dong-hyun Schneider) Newsgroups: comp.dsp Subject: [FLAME] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Feb04.152123.7361@rwth-aachen.de> Date: Sat, 04 Feb 1995 15:21:23 GMT Organization: RWTH Aachen Informatik NNTP-Posting-Host: rwth-aachen.de 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 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. MATLAB script available upon request via email. -- Dong-hyun Schneider Practical Peripherals 14.4 @ ISDN 64k bps "A soul is not exclusive to biology." From ssuzuki@netcom.com Sat Feb 04 20:30:23 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!netcom!ssuzuki From: ssuzuki@netcom.com (Sven Suzuki) Newsgroups: comp.dsp Subject: Re: [FLAME] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Feb04.203023.1492@netcom.com> Date: Sat, 04 Feb 1995 20:30:23 GMT References: <1995Feb04.152123.7361@rwth-aachen.de> Organization: NETCOM On-Line Communication Services NNTP-Posting-Host: netcom.com X-Newsreader: Netscape 1.1N Lines: 11 In article <1995Feb04.152123.7361@rwth-aachen.de>, dschneider@rwth-aachen.de (Dong-hyun Schneider) writes: > A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise! -- Sven Suzuki *PLONK* filter active for trolls. Commodore Amiga 500 (1MB OCS) - NetBSD 1.0 From mivanov@cam.ac.uk Tue Feb 07 00:00:23 1995 Path: ashpoly!cascade!transat!ukc!fennimore!cam!mivanov From: mivanov@cam.ac.uk (Morag Ivanov) Newsgroups: comp.dsp Subject: Re: [FLAME] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Feb07.000023.9371@cam.ac.uk> Date: Tue, 07 Feb 1995 00:00:23 GMT References: <1995Feb04.152123.7361@rwth-aachen.de> <1995Feb04.203023.1492@netcom.com> Organization: University of Cambridge Computer Laboratory NNTP-Posting-Host: cam.ac.uk X-Newsreader: Netscape 1.1N Lines: 10 In article <1995Feb04.203023.1492@netcom.com>, ssuzuki@netcom.com (Sven Suzuki) writes: > Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. > My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise! Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- Morag Ivanov "Hardware is temporary. The signal survives." Commodore Amiga 500 (1MB OCS) / AmigaOS 3.1 From hlopez@utexas.edu Wed Feb 08 09:04:23 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!utexas!hlopez From: hlopez@utexas.edu (Heather López) Newsgroups: comp.dsp Subject: Re: [FLAME] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Feb08.090423.7699@utexas.edu> Date: Wed, 08 Feb 1995 09:04:23 GMT References: <1995Feb04.152123.7361@rwth-aachen.de> <1995Feb04.203023.1492@netcom.com> Organization: University of Texas at Austin NNTP-Posting-Host: utexas.edu X-Newsreader: Netscape 1.1N Lines: 11 In article <1995Feb04.203023.1492@netcom.com>, ssuzuki@netcom.com (Sven Suzuki) writes: > Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. 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. PGP Public key available via finger or upon request. -- === Heather López === Dept of Electrical Engineering, University of Texas at Austin "The carrier frequency does not drift by accident."