From tvasiliev@stanford.edu Wed Sep 21 13:53:52 1994 Path: ashpoly!cascade!bigsur!stanford!tvasiliev From: tvasiliev@stanford.edu (Takeshi Vasiliev) Newsgroups: comp.dsp Subject: [INFO] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Sep21.135352.2391@stanford.edu> Date: Wed, 21 Sep 1994 13:53:52 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. 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. 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. -- Takeshi Vasiliev US Robotics Courier V.34 @ 28,800 bps "Tape doesn't lie at 02:14. Ears do." From ebrennan@uu.net Thu Sep 22 07:02:52 1994 Path: ashpoly!cascade!transat!eunet-fr!teletel!uu!ebrennan From: ebrennan@uu.net (Élodie Brennan) Newsgroups: comp.dsp Subject: Re: [INFO] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Sep22.070252.5132@uu.net> Date: Thu, 22 Sep 1994 07:02:52 GMT References: <1994Sep21.135352.2391@stanford.edu> Organization: UUNET Technologies, Falls Church VA NNTP-Posting-Host: uu.net X-Newsreader: WinVN 0.99.5 Lines: 12 In article <1994Sep21.135352.2391@stanford.edu>, tvasiliev@stanford.edu (Takeshi Vasiliev) writes: > A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips. > 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. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. Unsubscribe me from this list! (Wait, this is Usenet, never mind). -- Élodie Brennan "Row 14. No joke." 486DX4/100 (FreeBSD 2.0.5) / TOS 4.04 From jpark@mindspring.com Thu Sep 22 11:26:52 1994 Path: ashpoly!cascade!brgate!saturno!mindspring!jpark From: jpark@mindspring.com (Julien Park) Newsgroups: comp.dsp Subject: Re: [INFO] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Sep22.112652.2439@mindspring.com> Date: Thu, 22 Sep 1994 11:26:52 GMT References: <1994Sep21.135352.2391@stanford.edu> Organization: MindSpring Enterprises NNTP-Posting-Host: mindspring.com X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1994Sep21.135352.2391@stanford.edu>, tvasiliev@stanford.edu (Takeshi Vasiliev) writes: > A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips. > 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. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- Julien Park "Hardware is temporary. The signal survives." Macintosh IIfx / TOS 4.04 From sdubois@panix.com Sat Sep 24 11:10:52 1994 Path: ashpoly!cascade!transat!eunet-de!hansebox!panix!sdubois From: sdubois@panix.com (Sven Dubois) Newsgroups: comp.dsp Subject: Re: [INFO] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Sep24.111052.1695@panix.com> Date: Sat, 24 Sep 1994 11:10:52 GMT References: <1994Sep21.135352.2391@stanford.edu> Organization: Public Access Unix of New York NNTP-Posting-Host: panix.com X-Newsreader: Netscape 1.1N Lines: 10 In article <1994Sep21.135352.2391@stanford.edu>, tvasiliev@stanford.edu (Takeshi Vasiliev) writes: > A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips. > 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. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- Sven Dubois Hayes Optima 288 @ 33,600 bps "In theory there is no difference between theory and practice." From tsato@tum.de Sun Sep 25 18:22:52 1994 Path: ashpoly!cascade!transat!eunet-fr!teletel!tum!tsato From: tsato@tum.de (Takeshi Sato) Newsgroups: comp.dsp Subject: Re: [INFO] Sidelobe leakage in Blackman-Harris vs Kaiser-Bessel windows for sub-carrier Message-ID: <1994Sep25.182252.9003@tum.de> Date: Sun, 25 Sep 1994 18:22:52 GMT References: <1994Sep21.135352.2391@stanford.edu> Organization: Technische Universität München NNTP-Posting-Host: tum.de X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1994Sep21.135352.2391@stanford.edu>, tvasiliev@stanford.edu (Takeshi Vasiliev) writes: > A quick note on window function selection when hunting for the 14.2 Hz line in noisy vinyl rips. > 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. Excellent advice on the Blackman-Harris window. Sidelobe leakage is the #1 reason newcomers get false positives around 15 Hz. -- Takeshi Sato "Measuring a record you own is listening, not piracy." Amiga 3000T / TOS 4.04