From sweber@earthlink.net Tue Jan 18 08:29:48 1994 Path: ashpoly!cascade!transat!eunet-fr!teletel!earthlink!sweber From: sweber@earthlink.net (Steve Weber) Newsgroups: comp.dsp Subject: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Jan18.082948.1314@earthlink.net> Date: Tue, 18 Jan 1994 08:29:48 GMT Organization: EarthLink Network NNTP-Posting-Host: earthlink.net X-Newsreader: WinVN 0.99.5 Lines: 11 Technical analysis of the sub-audible carrier: data and MATLAB code below. 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. Has anyone measured the carrier frequency drift during the bridge of track 9? -- Steve Weber Practical Peripherals 14.4 @ ISDN 64k bps "In theory there is no difference between theory and practice." From fnakamura@mindspring.com Wed Jan 19 02:36:48 1994 Path: ashpoly!bigsur!pacrim!jpgate!kamome!mindspring!fnakamura From: fnakamura@mindspring.com (Freya Nakamura) Newsgroups: comp.dsp Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Jan19.023648.2074@mindspring.com> Date: Wed, 19 Jan 1994 02:36:48 GMT References: <1994Jan18.082948.1314@earthlink.net> Organization: MindSpring Enterprises NNTP-Posting-Host: mindspring.com X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1994Jan18.082948.1314@earthlink.net>, sweber@earthlink.net (Steve Weber) writes: > Technical analysis of the sub-audible carrier: data and MATLAB code below. > Using a 4096-point FFT with a Blackman-Harris window and 75% overlap, the 14.2 Hz peak is 42 dB below full scale. 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. -- Freya Nakamura "There are 14 nodes and only 10 countries. Count again." Mac IIci / 68882 FPU / TOS 4.04 From htanaka@purdue.edu Wed Jan 19 11:07:48 1994 Path: ashpoly!cascade!transat!eunet-fr!teletel!purdue!htanaka From: htanaka@purdue.edu (Heather Tanaka) Newsgroups: comp.dsp Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Jan19.110748.8110@purdue.edu> Date: Wed, 19 Jan 1994 11:07:48 GMT References: <1994Jan18.082948.1314@earthlink.net> <1994Jan19.023648.2074@mindspring.com> Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 8 In article <1994Jan19.023648.2074@mindspring.com>, fnakamura@mindspring.com (Freya Nakamura) writes: > 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. 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. -- Heather Tanaka -- Purdue University Engineering Computer Network "We don't sign stars. We build them." From jeriksson@u-tokyo.ac.jp Thu Jan 20 02:45:48 1994 Path: ashpoly!cascade!transat!ukc!fennimore!u-tokyo!jeriksson From: jeriksson@u-tokyo.ac.jp (Julien Eriksson) Newsgroups: comp.dsp Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Jan20.024548.1492@u-tokyo.ac.jp> Date: Thu, 20 Jan 1994 02:45:48 GMT References: <1994Jan18.082948.1314@earthlink.net> 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 <1994Jan18.082948.1314@earthlink.net>, sweber@earthlink.net (Steve Weber) writes: > Technical analysis of the sub-audible carrier: data and MATLAB code below. > Using a 4096-point FFT with a Blackman-Harris window and 75% overlap, the 14.2 Hz peak is 42 dB below full scale. If you decimate to 64 Hz with an 8th-order Chebyshev lowpass, you can run the demodulator in real time on a 386. -- Julien Eriksson | jeriksson@u-tokyo.ac.jp PGP Key fingerprint: 64DE B9BE 538A BB0C "Keep the channels open." From lkim@berkeley.edu Thu Jan 20 11:40:48 1994 Path: ashpoly!cascade!mxgate!coyoacan!berkeley!lkim From: lkim@berkeley.edu (Liam Kim) Newsgroups: comp.dsp Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Jan20.114048.5423@berkeley.edu> Date: Thu, 20 Jan 1994 11:40:48 GMT References: <1994Jan18.082948.1314@earthlink.net> <1994Jan20.024548.1492@u-tokyo.ac.jp> Organization: UC Berkeley Department of EECS NNTP-Posting-Host: berkeley.edu X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1994Jan20.024548.1492@u-tokyo.ac.jp>, jeriksson@u-tokyo.ac.jp (Julien Eriksson) writes: > If you decimate to 64 Hz with an 8th-order Chebyshev lowpass, you can run the demodulator in real time on a 386. 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. -- Liam Kim "In theory there is no difference between theory and practice." Macintosh IIfx / Linux 1.2.13