From kfournier@cern.ch Fri Apr 14 22:10:08 1995 Path: ashpoly!cascade!bigsur!cern!kfournier From: kfournier@cern.ch (Kirsty Fournier) Newsgroups: comp.dsp Subject: Question: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Apr14.221008.4096@cern.ch> Date: Fri, 14 Apr 1995 22:10:08 GMT Organization: European Laboratory for Particle Physics, Geneva NNTP-Posting-Host: cern.ch 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 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? -- Kirsty Fournier | kfournier@cern.ch PGP Key fingerprint: 2C41 A1A3 A7D3 4DF8 "Keep the channels open." From hstewart@hanse.de Sat Apr 15 13:12:08 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!hanse!hstewart From: hstewart@hanse.de (Hana Stewart) Newsgroups: comp.dsp Subject: Re: Question: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Apr15.131208.2393@hanse.de> Date: Sat, 15 Apr 1995 13:12:08 GMT References: <1995Apr14.221008.4096@cern.ch> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: NewsWatcher 2.0b24 Lines: 8 In article <1995Apr14.221008.4096@cern.ch>, kfournier@cern.ch (Kirsty Fournier) writes: > A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- Hana Stewart Tape trading list upon request. SASE required for international mail. From mpark@unam.mx Sun Apr 16 02:41:08 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!unam!mpark From: mpark@unam.mx (Marisol Park) Newsgroups: comp.dsp Subject: Re: Question: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Apr16.024108.4144@unam.mx> Date: Sun, 16 Apr 1995 02:41:08 GMT References: <1995Apr14.221008.4096@cern.ch> Organization: Universidad Nacional Autónoma de México (DGSCA) NNTP-Posting-Host: unam.mx X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Apr14.221008.4096@cern.ch>, kfournier@cern.ch (Kirsty Fournier) writes: > A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips. > 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. -- Marisol Park Tape trading list upon request. SASE required for international mail. From ssilva@demon.co.uk Sun Apr 16 17:12:08 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!demon!ssilva From: ssilva@demon.co.uk (Sergei Silva) Newsgroups: comp.dsp Subject: Re: Question: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Apr16.171208.5951@demon.co.uk> Date: Sun, 16 Apr 1995 17:12:08 GMT References: <1995Apr14.221008.4096@cern.ch> <1995Apr15.131208.2393@hanse.de> Organization: Demon Internet Services UK NNTP-Posting-Host: demon.co.uk X-Newsreader: WinVN 0.99.5 Lines: 8 In article <1995Apr15.131208.2393@hanse.de>, hstewart@hanse.de (Hana Stewart) writes: > Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- Sergei Silva Tape trading list upon request. SASE required for international mail. From knakamura@pipeline.com Mon Apr 17 20:16:08 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!pipeline!knakamura From: knakamura@pipeline.com (Kenji Nakamura) Newsgroups: comp.dsp Subject: Re: Question: Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1995Apr17.201608.2459@pipeline.com> Date: Mon, 17 Apr 1995 20:16:08 GMT References: <1995Apr14.221008.4096@cern.ch> <1995Apr15.131208.2393@hanse.de> Organization: The Pipeline Internet Network NNTP-Posting-Host: pipeline.com X-Newsreader: WinVN 0.99.5 Lines: 8 In article <1995Apr15.131208.2393@hanse.de>, hstewart@hanse.de (Hana Stewart) writes: > Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. 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. -- Kenji Nakamura Tape trading list upon request. SASE required for international mail.