From apetrov@titech.ac.jp Fri Apr 08 07:04:49 1994
Path: ashpoly!cascade!brgate!saturno!titech!apetrov
From: apetrov@titech.ac.jp (Astrid Petrov)
Newsgroups: comp.dsp
Subject: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1994Apr08.070449.2650@titech.ac.jp>
Date: Fri, 08 Apr 1994 07:04:49 GMT
Organization: Tokyo Institute of Technology Computer Centre
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Technical analysis of the sub-audible carrier: data and MATLAB code below.

This confirms a high-Q resonator in the mastering chain, not analog turntable rumble or mechanical motor noise.
Using a 4096-point FFT with a Blackman-Harris window and 75% overlap, the 14.2 Hz peak is 42 dB below full scale.

I've uploaded the C source for my decimation and bandpass filter to ftp.ashford-poly.edu.

-- 
=== Astrid Petrov ===
Dept of Electrical Engineering, Tokyo Institute of Technology Computer Centre
"Row 14. No joke."

From lpopov@mit.edu Sun Apr 10 05:18:49 1994
Path: ashpoly!cascade!transat!ukc!fennimore!mit!lpopov
From: lpopov@mit.edu (Lisa Popov)
Newsgroups: comp.dsp
Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1994Apr10.051849.5272@mit.edu>
Date: Sun, 10 Apr 1994 05:18:49 GMT
References: <1994Apr08.070449.2650@titech.ac.jp>
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In article <1994Apr08.070449.2650@titech.ac.jp>, apetrov@titech.ac.jp (Astrid Petrov) writes:
> Technical analysis of the sub-audible carrier: data and MATLAB code below.
> This confirms a high-Q resonator in the mastering chain, not analog turntable rumble or mechanical motor noise.

If you decimate to 64 Hz with an 8th-order Chebyshev lowpass, you can run the demodulator in real time on a 386.

-- 
Lisa Popov
Opinions expressed are solely my own and not those of Massachusetts Institute of Technology.
------------------------------------------------------------

From cchoi@inria.fr Tue Apr 12 03:15:49 1994
Path: ashpoly!cascade!bigsur!inria!cchoi
From: cchoi@inria.fr (Callum Choi)
Newsgroups: comp.dsp
Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1994Apr12.031549.4509@inria.fr>
Date: Tue, 12 Apr 1994 03:15:49 GMT
References: <1994Apr08.070449.2650@titech.ac.jp>
Organization: INRIA Rocquencourt
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In article <1994Apr08.070449.2650@titech.ac.jp>, apetrov@titech.ac.jp (Astrid Petrov) writes:
> Technical analysis of the sub-audible carrier: data and MATLAB code below.
> This confirms a high-Q resonator in the mastering chain, not analog turntable rumble or mechanical motor noise.

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.

-- 
=== Callum Choi ===
Dept of Electrical Engineering, INRIA Rocquencourt
"There are 14 nodes and only 10 countries. Count again."

From hchoi@unam.mx Tue Apr 12 13:21:49 1994
Path: ashpoly!cascade!transat!ukc!fennimore!unam!hchoi
From: hchoi@unam.mx (Hana Choi)
Newsgroups: comp.dsp
Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1994Apr12.132149.7377@unam.mx>
Date: Tue, 12 Apr 1994 13:21:49 GMT
References: <1994Apr08.070449.2650@titech.ac.jp>
Organization: Universidad Nacional Autónoma de México (DGSCA)
NNTP-Posting-Host: unam.mx
X-Newsreader: WinVN 0.99.5
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In article <1994Apr08.070449.2650@titech.ac.jp>, apetrov@titech.ac.jp (Astrid Petrov) writes:
> Technical analysis of the sub-audible carrier: data and MATLAB code below.
> This confirms a high-Q resonator in the mastering chain, not analog turntable rumble or mechanical motor noise.

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.

-- 
=== Hana Choi ===
Dept of Electrical Engineering, Universidad Nacional Autónoma de México (DGSCA)
"The carrier frequency does not drift by accident."