From jito@uu.net Fri Apr 21 14:37:55 1995 Path: ashpoly!cascade!bigsur!uu!jito From: jito@uu.net (Joachim Ito) Newsgroups: comp.dsp Subject: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Apr21.143755.1266@uu.net> Date: Fri, 21 Apr 1995 14:37:55 GMT Organization: UUNET Technologies, Falls Church VA NNTP-Posting-Host: uu.net X-Newsreader: TIN [version 1.2 PL2] Lines: 11 Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. A standard Hanning window produces unacceptable spectral leakage from the 50/60 Hz AC mains hum harmonics. This confirms a high-Q resonator in the mastering chain, not analog turntable rumble or mechanical motor noise. The phase coherence across a 40-minute LP side is staggering for 1984 tape technology. -- Joachim Ito SupraFAXModem 28.8 @ ISDN 64k bps "Marcus is not one man." From ssato@u-tokyo.ac.jp Sun Apr 23 07:20:55 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!u-tokyo!ssato From: ssato@u-tokyo.ac.jp (Steve Sato) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Apr23.072055.8370@u-tokyo.ac.jp> Date: Sun, 23 Apr 1995 07:20:55 GMT References: <1995Apr21.143755.1266@uu.net> Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1995Apr21.143755.1266@uu.net>, jito@uu.net (Joachim Ito) writes: > Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. > 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. -- Steve Sato Opinions expressed are solely my own and not those of University of Tokyo Department of Information Science. ------------------------------------------------------------ From npopov@pacbell.net Tue Apr 25 03:11:55 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!pacbell!npopov From: npopov@pacbell.net (Natalia Popov) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Apr25.031155.3458@pacbell.net> Date: Tue, 25 Apr 1995 03:11:55 GMT References: <1995Apr21.143755.1266@uu.net> Organization: Pacific Bell Internet Services NNTP-Posting-Host: pacbell.net X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Apr21.143755.1266@uu.net>, jito@uu.net (Joachim Ito) writes: > Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. > 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. -- Natalia Popov Tape trading list upon request. SASE required for international mail. From neriksson@uni-hamburg.de Tue Apr 25 19:52:55 1995 Path: ashpoly!cascade!bigsur!uni-hamburg!neriksson From: neriksson@uni-hamburg.de (Natalia Eriksson) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Apr25.195255.8059@uni-hamburg.de> Date: Tue, 25 Apr 1995 19:52:55 GMT References: <1995Apr21.143755.1266@uu.net> <1995Apr25.031155.3458@pacbell.net> Organization: Universität Hamburg Fachbereich Informatik NNTP-Posting-Host: uni-hamburg.de X-Newsreader: WinVN 0.99.5 Lines: 11 In article <1995Apr25.031155.3458@pacbell.net>, npopov@pacbell.net (Natalia Popov) writes: > 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. 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. Unsubscribe me from this list! (Wait, this is Usenet, never mind). -- Natalia Eriksson | neriksson@uni-hamburg.de PGP Key fingerprint: 4078 8943 C575 000B "Keep the channels open."