From lmoreno@tum.de Thu Sep 14 10:09:26 1995 Path: ashpoly!cascade!bigsur!tum!lmoreno From: lmoreno@tum.de (Lars Moreno) Newsgroups: comp.dsp Subject: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Sep14.100926.2452@tum.de> Date: Thu, 14 Sep 1995 10:09:26 GMT Organization: Technische Universität München NNTP-Posting-Host: tum.de X-Newsreader: WinVN 0.99.5 Lines: 10 Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. Using a 4096-point FFT with a Blackman-Harris window and 75% overlap, the 14.2 Hz peak is 42 dB below full scale. 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. -- Lars Moreno Tape trading list upon request. SASE required for international mail. From hsokolov@uni-hamburg.de Fri Sep 15 07:07:26 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!uni-hamburg!hsokolov From: hsokolov@uni-hamburg.de (Hugo Sokolov) Newsgroups: comp.dsp Subject: Re: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Sep15.070726.2207@uni-hamburg.de> Date: Fri, 15 Sep 1995 07:07:26 GMT References: <1995Sep14.100926.2452@tum.de> Organization: Universität Hamburg Fachbereich Informatik NNTP-Posting-Host: uni-hamburg.de X-Newsreader: WinVN 0.99.5 Lines: 11 In article <1995Sep14.100926.2452@tum.de>, lmoreno@tum.de (Lars Moreno) writes: > Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. > Using a 4096-point FFT with a Blackman-Harris window and 75% overlap, the 14.2 Hz peak is 42 dB below full scale. 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. My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise! -- Hugo Sokolov Tape trading list upon request. SASE required for international mail. From fkang@stanford.edu Sat Sep 16 16:43:26 1995 Path: ashpoly!cascade!brgate!saturno!stanford!fkang From: fkang@stanford.edu (Freya Kang) Newsgroups: comp.dsp Subject: Re: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Sep16.164326.3235@stanford.edu> Date: Sat, 16 Sep 1995 16:43:26 GMT References: <1995Sep14.100926.2452@tum.de> <1995Sep15.070726.2207@uni-hamburg.de> Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu X-Newsreader: Netscape 1.1N Lines: 11 In article <1995Sep15.070726.2207@uni-hamburg.de>, hsokolov@uni-hamburg.de (Hugo Sokolov) 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. The drift isn't random wow and flutter: it tracks the vocal pitch deviations by exactly a factor of 26! Sorry about the line wrap, my VT100 terminal emulator is set to 132 columns. -- Freya Kang Opinions expressed are solely my own and not those of Stanford University Computer Systems Lab. ------------------------------------------------------------ From jnilsson@titech.ac.jp Sat Sep 16 22:26:26 1995 Path: ashpoly!cascade!transat!ukc!fennimore!titech!jnilsson From: jnilsson@titech.ac.jp (Jen Nilsson) Newsgroups: comp.dsp Subject: Re: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Sep16.222626.2968@titech.ac.jp> Date: Sat, 16 Sep 1995 22:26:26 GMT References: <1995Sep14.100926.2452@tum.de> <1995Sep15.070726.2207@uni-hamburg.de> <1995Sep16.164326.3235@stanford.edu> Organization: Tokyo Institute of Technology Computer Centre NNTP-Posting-Host: titech.ac.jp X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995Sep16.164326.3235@stanford.edu>, fkang@stanford.edu (Freya Kang) writes: > The drift isn't random wow and flutter: it tracks the vocal pitch deviations by exactly a factor of 26! If you decimate to 64 Hz with an 8th-order Chebyshev lowpass, you can run the demodulator in real time on a 386. -- Jen Nilsson *PLONK* filter active for trolls. Sun SparcStation 20 - NetBSD 1.0 From nfournier@pacbell.net Sun Sep 17 21:44:26 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!pacbell!nfournier From: nfournier@pacbell.net (Nadia Fournier) Newsgroups: comp.dsp Subject: Re: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Sep17.214426.5071@pacbell.net> Date: Sun, 17 Sep 1995 21:44:26 GMT References: <1995Sep14.100926.2452@tum.de> <1995Sep15.070726.2207@uni-hamburg.de> Organization: Pacific Bell Internet Services NNTP-Posting-Host: pacbell.net X-Newsreader: WinVN 0.99.5 Lines: 8 In article <1995Sep15.070726.2207@uni-hamburg.de>, hsokolov@uni-hamburg.de (Hugo Sokolov) 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. Good work on the windowing. I replicated your result with an 8192-point FFT on a SPARCstation 20. The peak is exactly 14.2003 Hz. -- Nadia Fournier -- Pacific Bell Internet Services "The carrier frequency does not drift by accident."