From frodriguez@demon.co.uk Tue Jul 18 07:20:32 1995
Path: ashpoly!cascade!mxgate!coyoacan!demon!frodriguez
From: frodriguez@demon.co.uk (Freya Rodríguez)
Newsgroups: comp.dsp
Subject: [INFO] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1995Jul18.072032.9893@demon.co.uk>
Date: Tue, 18 Jul 1995 07:20:32 GMT
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Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line.

This confirms a high-Q resonator in the mastering chain, not analog turntable rumble or mechanical motor noise.
With a 12th-order Burg AR model, the pole is located at z = 0.9992 * exp(j * 2 * pi * 14.2 / Fs).

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

-- 
Freya Rodríguez
Tape trading list upon request. SASE required for international mail.

From kgonzalez@cmu.edu Tue Jul 18 20:11:32 1995
Path: ashpoly!cascade!transat!ukc!fennimore!cmu!kgonzalez
From: kgonzalez@cmu.edu (Katrin González)
Newsgroups: comp.dsp
Subject: Re: [INFO] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1995Jul18.201132.1300@cmu.edu>
Date: Tue, 18 Jul 1995 20:11:32 GMT
References: <1995Jul18.072032.9893@demon.co.uk>
Organization: Carnegie Mellon University School of CS
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In article <1995Jul18.072032.9893@demon.co.uk>, frodriguez@demon.co.uk (Freya Rodríguez) writes:
> Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line.
> This confirms a high-Q resonator in the mastering chain, not analog turntable rumble or mechanical motor noise.

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

-- 
Katrin González -- Carnegie Mellon University School of CS
"When every node is whole, the channel opens."