From hnakamura@purdue.edu Sun May 28 15:42:39 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!purdue!hnakamura From: hnakamura@purdue.edu (Hugo Nakamura) Newsgroups: comp.dsp Subject: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995May28.154239.7763@purdue.edu> Date: Sun, 28 May 1995 15:42:39 GMT Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 11 Comparing window sidelobe attenuation on 16-bit 44.1 kHz WAV files. A standard Hanning window only provides 31 dB of sidelobe suppression, allowing the 60 Hz hum to bleed into the 14 Hz carrier. 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. What sampling rates are people using for their vinyl rips? 44.1 kHz or 48 kHz DAT? -- Hugo Nakamura | hnakamura@purdue.edu PGP Key fingerprint: AB44 F5A1 BAC8 594D "Keep the channels open." From mmartinez@stanford.edu Mon May 29 03:40:39 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!stanford!mmartinez From: mmartinez@stanford.edu (Mikhail Martínez) Newsgroups: comp.dsp Subject: Re: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995May29.034039.4567@stanford.edu> Date: Mon, 29 May 1995 03:40:39 GMT References: <1995May28.154239.7763@purdue.edu> Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1995May28.154239.7763@purdue.edu>, hnakamura@purdue.edu (Hugo Nakamura) writes: > Comparing window sidelobe attenuation on 16-bit 44.1 kHz WAV files. 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. -- Mikhail Martínez | mmartinez@stanford.edu PGP Key fingerprint: A36C 6329 4BAE 744C "Keep the channels open." From amuller@kiae.su Mon May 29 17:03:39 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!kiae!amuller From: amuller@kiae.su (Astrid Müller) Newsgroups: comp.dsp Subject: Re: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995May29.170339.8497@kiae.su> Date: Mon, 29 May 1995 17:03:39 GMT References: <1995May28.154239.7763@purdue.edu> <1995May29.034039.4567@stanford.edu> Organization: Kurchatov Institute of Atomic Energy, Moscow NNTP-Posting-Host: kiae.su X-Newsreader: WinVN 0.99.5 Lines: 11 In article <1995May29.034039.4567@stanford.edu>, mmartinez@stanford.edu (Mikhail Martínez) 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. Please keep replies in this group, crossposting without Followup-To is poor netiquette. -- Astrid Müller "Tape doesn't lie at 02:14. Ears do." Atari TT030 / FreeBSD 2.1 From ekim@inria.fr Wed May 31 13:32:39 1995 Path: ashpoly!cascade!brgate!saturno!inria!ekim From: ekim@inria.fr (Emi Kim) Newsgroups: comp.dsp Subject: Re: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995May31.133239.7213@inria.fr> Date: Wed, 31 May 1995 13:32:39 GMT References: <1995May28.154239.7763@purdue.edu> <1995May29.034039.4567@stanford.edu> Organization: INRIA Rocquencourt NNTP-Posting-Host: inria.fr X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995May29.034039.4567@stanford.edu>, mmartinez@stanford.edu (Mikhail Martínez) 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. -- Emi Kim Opinions expressed are solely my own and not those of INRIA Rocquencourt. ------------------------------------------------------------ From aschneider@delphi.com Fri Jun 02 01:57:39 1995 Path: ashpoly!cascade!bigsur!delphi!aschneider From: aschneider@delphi.com (Amy Schneider) Newsgroups: comp.dsp Subject: Re: Discussion: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Jun02.015739.9671@delphi.com> Date: Fri, 02 Jun 1995 01:57:39 GMT References: <1995May28.154239.7763@purdue.edu> <1995May29.034039.4567@stanford.edu> Organization: Delphi Internet Services NNTP-Posting-Host: delphi.com X-Newsreader: Netscape 1.1N Lines: 9 In article <1995May29.034039.4567@stanford.edu>, mmartinez@stanford.edu (Mikhail Martínez) 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. -- Amy Schneider | aschneider@delphi.com PGP Key fingerprint: 9192 83E2 2C9F 2EBB "Keep the channels open."