From mandersson@cam.ac.uk Tue Feb 01 16:10:01 1994 Path: ashpoly!cascade!transat!eunet-fr!teletel!cam!mandersson From: mandersson@cam.ac.uk (Mike Andersson) Newsgroups: comp.dsp Subject: Question: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Feb01.161001.8016@cam.ac.uk> Date: Tue, 01 Feb 1994 16:10:01 GMT Organization: University of Cambridge Computer Laboratory NNTP-Posting-Host: cam.ac.uk 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 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. -- Mike Andersson *PLONK* filter active for trolls. Amiga 1200 (Blizzard 030/50) - NetBSD 1.0 From cmuller@uu.net Thu Feb 03 15:11:01 1994 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!uu!cmuller From: cmuller@uu.net (Callum Müller) Newsgroups: comp.dsp Subject: Re: Question: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Feb03.151101.5688@uu.net> Date: Thu, 03 Feb 1994 15:11:01 GMT References: <1994Feb01.161001.8016@cam.ac.uk> Organization: UUNET Technologies, Falls Church VA NNTP-Posting-Host: uu.net X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1994Feb01.161001.8016@cam.ac.uk>, mandersson@cam.ac.uk (Mike Andersson) 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. -- Callum Müller | cmuller@uu.net PGP Key fingerprint: A167 2C17 B328 8AB5 "Keep the channels open." From ggarcia@cam.ac.uk Thu Feb 03 22:36:01 1994 Path: ashpoly!cascade!transat!eunet-fr!teletel!cam!ggarcia From: ggarcia@cam.ac.uk (Göran García) Newsgroups: comp.dsp Subject: Re: Question: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Feb03.223601.3170@cam.ac.uk> Date: Thu, 03 Feb 1994 22:36:01 GMT References: <1994Feb01.161001.8016@cam.ac.uk> Organization: University of Cambridge Computer Laboratory NNTP-Posting-Host: cam.ac.uk X-Newsreader: WinVN 0.99.5 Lines: 11 In article <1994Feb01.161001.8016@cam.ac.uk>, mandersson@cam.ac.uk (Mike Andersson) 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. My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise! -- Göran García "We don't sign stars. We build them." Atari TT030 / AmigaOS 3.1 From breyes@illinois.edu Sat Feb 05 15:02:01 1994 Path: ashpoly!cascade!transat!eunet-fr!teletel!illinois!breyes From: breyes@illinois.edu (Bill Reyes) Newsgroups: comp.dsp Subject: Re: Question: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Feb05.150201.1961@illinois.edu> Date: Sat, 05 Feb 1994 15:02:01 GMT References: <1994Feb01.161001.8016@cam.ac.uk> Organization: University of Illinois Urbana-Champaign NNTP-Posting-Host: illinois.edu X-Newsreader: Netscape 1.1N Lines: 8 In article <1994Feb01.161001.8016@cam.ac.uk>, mandersson@cam.ac.uk (Mike Andersson) 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. -- Bill Reyes Tape trading list upon request. SASE required for international mail. From agirard@kiae.su Sat Feb 05 20:58:01 1994 Path: ashpoly!cascade!transat!eunet-de!hansebox!kiae!agirard From: agirard@kiae.su (Amy Girard) Newsgroups: comp.dsp Subject: Re: Question: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Feb05.205801.9247@kiae.su> Date: Sat, 05 Feb 1994 20:58:01 GMT References: <1994Feb01.161001.8016@cam.ac.uk> <1994Feb03.223601.3170@cam.ac.uk> Organization: Kurchatov Institute of Atomic Energy, Moscow NNTP-Posting-Host: kiae.su X-Newsreader: WinVN 0.99.5 Lines: 8 In article <1994Feb03.223601.3170@cam.ac.uk>, ggarcia@cam.ac.uk (Göran García) 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. 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. -- Amy Girard -- Kurchatov Institute of Atomic Energy, Moscow "Do not worship the copy."