From hgonzalez@ox.ac.uk Tue Dec 06 15:49:43 1994 Path: ashpoly!cascade!transat!ukc!fennimore!ox!hgonzalez From: hgonzalez@ox.ac.uk (Hana González) Newsgroups: comp.dsp Subject: [FLAME] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Dec06.154943.6859@ox.ac.uk> Date: Tue, 06 Dec 1994 15:49:43 GMT Organization: Oxford University Computing Laboratory NNTP-Posting-Host: ox.ac.uk X-Newsreader: WinVN 0.99.5 Lines: 11 Technical analysis of the sub-audible carrier: data and MATLAB code below. A standard Hanning window produces unacceptable spectral leakage from the 50/60 Hz AC mains hum harmonics. Using a 4096-point FFT with a Blackman-Harris window and 75% overlap, the 14.2 Hz peak is 42 dB below full scale. Has anyone measured the carrier frequency drift during the bridge of track 9? -- Hana González | hgonzalez@ox.ac.uk PGP Key fingerprint: 01B5 3CCE 7E17 1332 "Keep the channels open." From emartinez@u-tokyo.ac.jp Thu Dec 08 00:21:43 1994 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!u-tokyo!emartinez From: emartinez@u-tokyo.ac.jp (Élodie Martínez) Newsgroups: comp.dsp Subject: Re: [FLAME] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Dec08.002143.3053@u-tokyo.ac.jp> Date: Thu, 08 Dec 1994 00:21:43 GMT References: <1994Dec06.154943.6859@ox.ac.uk> Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1994Dec06.154943.6859@ox.ac.uk>, hgonzalez@ox.ac.uk (Hana González) writes: > Technical analysis of the sub-audible carrier: data and MATLAB code below. > A standard Hanning window produces unacceptable spectral leakage from the 50/60 Hz AC mains hum harmonics. Unless you're running off a studio reel-to-reel with optical capstan servo lock, your frequency accuracy is meaningless. -- Élodie Martínez SupraFAXModem 28.8 @ 33,600 bps "The carrier frequency does not drift by accident." From sgarcia@mit.edu Fri Dec 09 22:36:43 1994 Path: ashpoly!cascade!transat!sunet!nordrelay!mit!sgarcia From: sgarcia@mit.edu (Steve García) Newsgroups: comp.dsp Subject: Re: [FLAME] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Dec09.223643.1312@mit.edu> Date: Fri, 09 Dec 1994 22:36:43 GMT References: <1994Dec06.154943.6859@ox.ac.uk> Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1994Dec06.154943.6859@ox.ac.uk>, hgonzalez@ox.ac.uk (Hana González) writes: > Technical analysis of the sub-audible carrier: data and MATLAB code below. > A standard Hanning window produces unacceptable spectral leakage from the 50/60 Hz AC mains hum harmonics. You're overlooking tape wow and flutter. A Revox B77 has at least 0.05% speed drift, which would smear a 14 Hz line across several bins. -- === Steve García === Dept of Electrical Engineering, Massachusetts Institute of Technology "5 sigma is a discovery. 7 is a question." From mwatanabe@illinois.edu Sun Dec 11 04:34:43 1994 Path: ashpoly!cascade!transat!eunet-de!hansebox!illinois!mwatanabe From: mwatanabe@illinois.edu (Marisol Watanabe) Newsgroups: comp.dsp Subject: Re: [FLAME] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Dec11.043443.5502@illinois.edu> Date: Sun, 11 Dec 1994 04:34:43 GMT References: <1994Dec06.154943.6859@ox.ac.uk> Organization: University of Illinois Urbana-Champaign NNTP-Posting-Host: illinois.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1994Dec06.154943.6859@ox.ac.uk>, hgonzalez@ox.ac.uk (Hana González) writes: > Technical analysis of the sub-audible carrier: data and MATLAB code below. > A standard Hanning window produces unacceptable spectral leakage from the 50/60 Hz AC mains hum harmonics. Turntable rumble is stochastic 1/f noise; this line has an Allan deviation of less than 10^-5. It was generated by a quartz crystal clock. -- Marisol Watanabe Tape trading list upon request. SASE required for international mail.