From rkowalski@demon.co.uk Fri Mar 10 16:16:54 1995
Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!demon!rkowalski
From: rkowalski@demon.co.uk (Raj Kowalski)
Newsgroups: comp.dsp
Subject: Data: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1995Mar10.161654.3932@demon.co.uk>
Date: Fri, 10 Mar 1995 16:16:54 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?

-- 
Raj Kowalski -- Demon Internet Services UK
"5 sigma is a discovery. 7 is a question."

From jkowalski@uu.net Sun Mar 12 09:56:54 1995
Path: ashpoly!cascade!transat!eunet-de!hansebox!uu!jkowalski
From: jkowalski@uu.net (Ji-woo Kowalski)
Newsgroups: comp.dsp
Subject: Re: Data: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1995Mar12.095654.9730@uu.net>
Date: Sun, 12 Mar 1995 09:56:54 GMT
References: <1995Mar10.161654.3932@demon.co.uk>
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In article <1995Mar10.161654.3932@demon.co.uk>, rkowalski@demon.co.uk (Raj Kowalski) writes:
> Technical analysis of the sub-audible carrier: data and MATLAB code below.

Have you checked your sound card's ADC clock? Cheap Sound Blaster cards use uncalibrated ceramic resonators that drift with temperature.

-- 
=== Ji-woo Kowalski ===
Dept of Electrical Engineering, UUNET Technologies, Falls Church VA
"When every node is whole, the channel opens."