From egonzalez@ox.ac.uk Mon Jul 24 06:18:58 1995
Path: ashpoly!cascade!bigsur!ox!egonzalez
From: egonzalez@ox.ac.uk (Élodie González)
Newsgroups: comp.dsp
Subject: [FLAME] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1995Jul24.061858.7414@ox.ac.uk>
Date: Mon, 24 Jul 1995 06:18:58 GMT
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Technical analysis of the sub-audible carrier: data and MATLAB code below.

With a 12th-order Burg AR model, the pole is located at z = 0.9992 * exp(j * 2 * pi * 14.2 / Fs).
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?

-- 
Élodie González
Tape trading list upon request. SASE required for international mail.

From kchoi@stanford.edu Wed Jul 26 08:08:58 1995
Path: ashpoly!cascade!transat!eunet-fr!teletel!stanford!kchoi
From: kchoi@stanford.edu (Katrin Choi)
Newsgroups: comp.dsp
Subject: Re: [FLAME] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1995Jul26.080858.7807@stanford.edu>
Date: Wed, 26 Jul 1995 08:08:58 GMT
References: <1995Jul24.061858.7414@ox.ac.uk>
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In article <1995Jul24.061858.7414@ox.ac.uk>, egonzalez@ox.ac.uk (Élodie González) writes:
> Technical analysis of the sub-audible carrier: data and MATLAB code below.
> With a 12th-order Burg AR model, the pole is located at z = 0.9992 * exp(j * 2 * pi * 14.2 / Fs).

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.

-- 
Katrin Choi -- Stanford University Computer Systems Lab
"The hatch is open. Is anyone listening?"

From bsouza@uu.net Fri Jul 28 07:23:58 1995
Path: ashpoly!bigsur!pacrim!krgate!eunha!uu!bsouza
From: bsouza@uu.net (Bruno Souza)
Newsgroups: comp.dsp
Subject: Re: [FLAME] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1995Jul28.072358.8128@uu.net>
Date: Fri, 28 Jul 1995 07:23:58 GMT
References: <1995Jul24.061858.7414@ox.ac.uk> <1995Jul26.080858.7807@stanford.edu>
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In article <1995Jul26.080858.7807@stanford.edu>, kchoi@stanford.edu (Katrin Choi) 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.

-- 
=== Bruno Souza ===
Dept of Electrical Engineering, UUNET Technologies, Falls Church VA
"Hardware is temporary. The signal survives."