From mkang@clari.net Sat Jul 09 10:46:42 1994
Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!clari!mkang
From: mkang@clari.net (Mathieu Kang)
Newsgroups: comp.dsp
Subject: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1994Jul09.104642.1099@clari.net>
Date: Sat, 09 Jul 1994 10:46:42 GMT
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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.

Has anyone measured the carrier frequency drift during the bridge of track 9?

-- 
Mathieu Kang <mkang@clari.net>
"We don't sign stars. We build them."
Atari TT030 / SunOS 4.1.4

From eoliveira@unam.mx Sun Jul 10 21:14:42 1994
Path: ashpoly!cascade!transat!ukc!fennimore!unam!eoliveira
From: eoliveira@unam.mx (Élodie Oliveira)
Newsgroups: comp.dsp
Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1994Jul10.211442.6355@unam.mx>
Date: Sun, 10 Jul 1994 21:14:42 GMT
References: <1994Jul09.104642.1099@clari.net>
Organization: Universidad Nacional Autónoma de México (DGSCA)
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In article <1994Jul09.104642.1099@clari.net>, mkang@clari.net (Mathieu Kang) writes:
> Technical analysis of the sub-audible carrier: data and MATLAB code below.

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

-- 
=== Élodie Oliveira ===
Dept of Electrical Engineering, Universidad Nacional Autónoma de México (DGSCA)
"Do not worship the copy."