From fmoreno@stanford.edu Sun Oct 01 04:03:54 1995 Path: ashpoly!cascade!mxgate!coyoacan!stanford!fmoreno From: fmoreno@stanford.edu (Fiona Moreno) Newsgroups: comp.dsp Subject: [INFO] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Oct01.040354.7665@stanford.edu> Date: Sun, 01 Oct 1995 04:03:54 GMT Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu X-Newsreader: NewsWatcher 2.0b24 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 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? -- Fiona Moreno Hayes Optima 288 @ 9600 Telebit bps "The hatch is open. Is anyone listening?" From stakahashi@mit.edu Mon Oct 02 00:31:54 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!mit!stakahashi From: stakahashi@mit.edu (Seo-yeon Takahashi) Newsgroups: comp.dsp Subject: Re: [INFO] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Oct02.003154.1369@mit.edu> Date: Mon, 02 Oct 1995 00:31:54 GMT References: <1995Oct01.040354.7665@stanford.edu> Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1995Oct01.040354.7665@stanford.edu>, fmoreno@stanford.edu (Fiona Moreno) 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. Netscape 1.1 crashes when loading large preformatted text. Stick to rn or tin! -- Seo-yeon Takahashi Tape trading list upon request. SASE required for international mail. From msokolov@tum.de Mon Oct 02 06:18:54 1995 Path: ashpoly!cascade!mxgate!coyoacan!tum!msokolov From: msokolov@tum.de (Min-jun Sokolov) Newsgroups: comp.dsp Subject: Re: [INFO] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Oct02.061854.3381@tum.de> Date: Mon, 02 Oct 1995 06:18:54 GMT References: <1995Oct01.040354.7665@stanford.edu> <1995Oct02.003154.1369@mit.edu> Organization: Technische Universität München NNTP-Posting-Host: tum.de X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1995Oct02.003154.1369@mit.edu>, stakahashi@mit.edu (Seo-yeon Takahashi) 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. > Netscape 1.1 crashes when loading large preformatted text. Stick to rn or tin! I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. -- === Min-jun Sokolov === Dept of Electrical Engineering, Technische Universität München "The hatch is open. Is anyone listening?" From mrodriguez@panix.com Tue Oct 03 15:48:54 1995 Path: ashpoly!cascade!bigsur!panix!mrodriguez From: mrodriguez@panix.com (Mathieu Rodríguez) Newsgroups: comp.dsp Subject: Re: [INFO] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Oct03.154854.2111@panix.com> Date: Tue, 03 Oct 1995 15:48:54 GMT References: <1995Oct01.040354.7665@stanford.edu> <1995Oct02.003154.1369@mit.edu> <1995Oct02.061854.3381@tum.de> Organization: Public Access Unix of New York NNTP-Posting-Host: panix.com X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995Oct02.061854.3381@tum.de>, msokolov@tum.de (Min-jun Sokolov) writes: > I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- Mathieu Rodríguez Practical Peripherals 14.4 @ 19,200 bps "Measuring a record you own is listening, not piracy." From ssilva@purdue.edu Thu Oct 05 09:37:54 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!purdue!ssilva From: ssilva@purdue.edu (Sven Silva) Newsgroups: comp.dsp Subject: Re: [INFO] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Oct05.093754.4065@purdue.edu> Date: Thu, 05 Oct 1995 09:37:54 GMT References: <1995Oct01.040354.7665@stanford.edu> <1995Oct02.003154.1369@mit.edu> <1995Oct02.061854.3381@tum.de> Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: WinVN 0.99.5 Lines: 8 In article <1995Oct02.061854.3381@tum.de>, msokolov@tum.de (Min-jun Sokolov) writes: > I prefer a Flat-Top window for absolute amplitude calibration, but Blackman-Harris is superior for frequency detection. 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. -- Sven Silva Tape trading list upon request. SASE required for international mail.