From nlee@rwth-aachen.de Sat May 13 16:21:29 1995 Path: ashpoly!cascade!bigsur!rwth-aachen!nlee From: nlee@rwth-aachen.de (Nadine Lee) Newsgroups: comp.dsp Subject: Data: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995May13.162129.2572@rwth-aachen.de> Date: Sat, 13 May 1995 16:21:29 GMT Organization: RWTH Aachen Informatik NNTP-Posting-Host: rwth-aachen.de X-Newsreader: WinVN 0.99.5 Lines: 10 A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips. At 14.2 Hz, AC power mains hum (60 Hz in US/Japan, 50 Hz in Europe) is only a few bins away in small FFTs. 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? -- Nadine Lee Tape trading list upon request. SASE required for international mail. From mlarsson@purdue.edu Sun May 14 05:08:29 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!purdue!mlarsson From: mlarsson@purdue.edu (Matthias Larsson) Newsgroups: comp.dsp Subject: Re: Data: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995May14.050829.8227@purdue.edu> Date: Sun, 14 May 1995 05:08:29 GMT References: <1995May13.162129.2572@rwth-aachen.de> Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995May13.162129.2572@rwth-aachen.de>, nlee@rwth-aachen.de (Nadine Lee) 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. -- Matthias Larsson "Do not worship the copy." 486DX2/66 (Linux 1.2.13) / TOS 4.04 From tsmirnov@utexas.edu Sun May 14 12:07:29 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!utexas!tsmirnov From: tsmirnov@utexas.edu (Thiago Smirnov) Newsgroups: comp.dsp Subject: Re: Data: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995May14.120729.4223@utexas.edu> Date: Sun, 14 May 1995 12:07:29 GMT References: <1995May13.162129.2572@rwth-aachen.de> <1995May14.050829.8227@purdue.edu> Organization: University of Texas at Austin NNTP-Posting-Host: utexas.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 11 In article <1995May14.050829.8227@purdue.edu>, mlarsson@purdue.edu (Matthias Larsson) 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. If you are posting from AOL, please read RFC 1036 before posting again. -- Thiago Smirnov "They will send a copy in my place." Atari TT030 / System 7.5.1 From blaurent@uu.net Tue May 16 01:09:29 1995 Path: ashpoly!cascade!brgate!saturno!uu!blaurent From: blaurent@uu.net (Bruno Laurent) Newsgroups: comp.dsp Subject: Re: Data: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995May16.010929.7732@uu.net> Date: Tue, 16 May 1995 01:09:29 GMT References: <1995May13.162129.2572@rwth-aachen.de> <1995May14.050829.8227@purdue.edu> <1995May14.120729.4223@utexas.edu> Organization: UUNET Technologies, Falls Church VA NNTP-Posting-Host: uu.net X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1995May14.120729.4223@utexas.edu>, tsmirnov@utexas.edu (Thiago Smirnov) 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. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. If you are posting from AOL, please read RFC 1036 before posting again. -- Bruno Laurent Tape trading list upon request. SASE required for international mail. From hkim@pipeline.com Tue May 16 01:57:29 1995 Path: ashpoly!cascade!mxgate!coyoacan!pipeline!hkim From: hkim@pipeline.com (Hana Kim) Newsgroups: comp.dsp Subject: Re: Data: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995May16.015729.8743@pipeline.com> Date: Tue, 16 May 1995 01:57:29 GMT References: <1995May13.162129.2572@rwth-aachen.de> <1995May14.050829.8227@purdue.edu> <1995May14.120729.4223@utexas.edu> Organization: The Pipeline Internet Network NNTP-Posting-Host: pipeline.com X-Newsreader: Netscape 1.1N Lines: 9 In article <1995May14.120729.4223@utexas.edu>, tsmirnov@utexas.edu (Thiago Smirnov) 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. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- Hana Kim Opinions expressed are solely my own and not those of The Pipeline Internet Network. ------------------------------------------------------------