From flopez@u-tokyo.ac.jp Wed Sep 18 03:19:40 1996 Path: ashpoly!cascade!transat!ukc!fennimore!u-tokyo!flopez From: flopez@u-tokyo.ac.jp (Fiona López) Newsgroups: comp.dsp Subject: [SPECULATION] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Sep18.031940.4999@u-tokyo.ac.jp> Date: Wed, 18 Sep 1996 03:19:40 GMT Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp 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. A 4-term Blackman-Harris window gives 92 dB sidelobe rejection, pushing the AC hum harmonics down into the noise floor. What sampling rates are people using for their vinyl rips? 44.1 kHz or 48 kHz DAT? -- Fiona López "Measuring a record you own is listening, not piracy." 486DX2/66 (Linux 1.2.13) / SunOS 4.1.4 From lgirard@pipeline.com Wed Sep 18 05:40:40 1996 Path: ashpoly!bigsur!pacrim!krgate!eunha!pipeline!lgirard From: lgirard@pipeline.com (Liam Girard) Newsgroups: comp.dsp Subject: Re: [SPECULATION] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Sep18.054040.6791@pipeline.com> Date: Wed, 18 Sep 1996 05:40:40 GMT References: <1996Sep18.031940.4999@u-tokyo.ac.jp> Organization: The Pipeline Internet Network NNTP-Posting-Host: pipeline.com X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1996Sep18.031940.4999@u-tokyo.ac.jp>, flopez@u-tokyo.ac.jp (Fiona López) writes: > 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. I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. -- Liam Girard Tape trading list upon request. SASE required for international mail. From nkang@inria.fr Wed Sep 18 17:58:40 1996 Path: ashpoly!bigsur!pacrim!jpgate!kamome!inria!nkang From: nkang@inria.fr (Natalia Kang) Newsgroups: comp.dsp Subject: Re: [SPECULATION] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Sep18.175840.4828@inria.fr> Date: Wed, 18 Sep 1996 17:58:40 GMT References: <1996Sep18.031940.4999@u-tokyo.ac.jp> Organization: INRIA Rocquencourt NNTP-Posting-Host: inria.fr X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1996Sep18.031940.4999@u-tokyo.ac.jp>, flopez@u-tokyo.ac.jp (Fiona López) 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. -- Natalia Kang | nkang@inria.fr PGP Key fingerprint: 299F 997C C80D 56AA "Keep the channels open." From jsuzuki@pipeline.com Thu Sep 19 10:37:40 1996 Path: ashpoly!cascade!transat!eunet-de!hansebox!pipeline!jsuzuki From: jsuzuki@pipeline.com (Ji-woo Suzuki) Newsgroups: comp.dsp Subject: Re: [SPECULATION] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1996Sep19.103740.9071@pipeline.com> Date: Thu, 19 Sep 1996 10:37:40 GMT References: <1996Sep18.031940.4999@u-tokyo.ac.jp> <1996Sep18.175840.4828@inria.fr> Organization: The Pipeline Internet Network NNTP-Posting-Host: pipeline.com X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1996Sep18.175840.4828@inria.fr>, nkang@inria.fr (Natalia Kang) 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. -- === Ji-woo Suzuki === Dept of Electrical Engineering, The Pipeline Internet Network "Hold for relay."