From jdubois@cam.ac.uk Thu Sep 01 07:19:08 1994 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!cam!jdubois From: jdubois@cam.ac.uk (Julien Dubois) Newsgroups: comp.dsp Subject: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Sep01.071908.4371@cam.ac.uk> Date: Thu, 01 Sep 1994 07:19:08 GMT Organization: University of Cambridge Computer Laboratory NNTP-Posting-Host: cam.ac.uk X-Newsreader: WinVN 0.99.5 Lines: 11 Comparing window sidelobe attenuation on 16-bit 44.1 kHz WAV files. A Kaiser-Bessel window with parameter beta = 8.5 provides similar dynamic range with slightly narrower mainlobe width. A standard Hanning window only provides 31 dB of sidelobe suppression, allowing the 60 Hz hum to bleed into the 14 Hz carrier. Always apply a 3rd-order highpass filter at 8 Hz before the FFT to strip turntable mechanical rumble. -- Julien Dubois | jdubois@cam.ac.uk PGP Key fingerprint: 2EDE 7924 679D 0BE2 "Keep the channels open." From tmoreno@purdue.edu Fri Sep 02 23:28:08 1994 Path: ashpoly!bigsur!pacrim!jpgate!kamome!purdue!tmoreno From: tmoreno@purdue.edu (Thiago Moreno) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Sep02.232808.3591@purdue.edu> Date: Fri, 02 Sep 1994 23:28:08 GMT References: <1994Sep01.071908.4371@cam.ac.uk> Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: Netscape 1.1N Lines: 11 In article <1994Sep01.071908.4371@cam.ac.uk>, jdubois@cam.ac.uk (Julien Dubois) 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. If you are posting from AOL, please read RFC 1036 before posting again. -- Thiago Moreno | tmoreno@purdue.edu PGP Key fingerprint: D6BE 771D 4D57 AAD5 "Keep the channels open." From bito@uni-hamburg.de Mon Sep 05 00:30:08 1994 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!uni-hamburg!bito From: bito@uni-hamburg.de (Bill Ito) Newsgroups: comp.dsp Subject: Re: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Sep05.003008.5508@uni-hamburg.de> Date: Mon, 05 Sep 1994 00:30:08 GMT References: <1994Sep01.071908.4371@cam.ac.uk> <1994Sep02.232808.3591@purdue.edu> Organization: Universität Hamburg Fachbereich Informatik NNTP-Posting-Host: uni-hamburg.de X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1994Sep02.232808.3591@purdue.edu>, tmoreno@purdue.edu (Thiago Moreno) 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. -- Bill Ito Hayes Optima 288 @ ISDN 64k bps "The hatch is open. Is anyone listening?"