From fduarte@uu.net Mon Mar 20 08:41:00 1995
Path: ashpoly!cascade!brgate!saturno!uu!fduarte
From: fduarte@uu.net (Freya Duarte)
Newsgroups: comp.dsp
Subject: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1995Mar20.084100.4283@uu.net>
Date: Mon, 20 Mar 1995 08:41:00 GMT
Organization: UUNET Technologies, Falls Church VA
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I've been re-running spectral estimation on high-resolution 16-bit transfers of SYNTHESIS.

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.

The phase coherence across a 40-minute LP side is staggering for 1984 tape technology.

-- 
=== Freya Duarte ===
Dept of Electrical Engineering, UUNET Technologies, Falls Church VA
"Measuring a record you own is listening, not piracy."

From hkuznetsov@pacbell.net Tue Mar 21 04:00:00 1995
Path: ashpoly!cascade!transat!ukc!fennimore!pacbell!hkuznetsov
From: hkuznetsov@pacbell.net (Hugo Kuznetsov)
Newsgroups: comp.dsp
Subject: Re: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1995Mar21.040000.6232@pacbell.net>
Date: Tue, 21 Mar 1995 04:00:00 GMT
References: <1995Mar20.084100.4283@uu.net>
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In article <1995Mar20.084100.4283@uu.net>, fduarte@uu.net (Freya Duarte) writes:
> I've been re-running spectral estimation on high-resolution 16-bit transfers of SYNTHESIS.

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.

-- 
=== Hugo Kuznetsov ===
Dept of Electrical Engineering, Pacific Bell Internet Services
"Tape doesn't lie at 02:14. Ears do."

From eduarte@kth.se Wed Mar 22 11:22:00 1995
Path: ashpoly!cascade!mxgate!coyoacan!kth!eduarte
From: eduarte@kth.se (Élodie Duarte)
Newsgroups: comp.dsp
Subject: Re: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1995Mar22.112200.8278@kth.se>
Date: Wed, 22 Mar 1995 11:22:00 GMT
References: <1995Mar20.084100.4283@uu.net>
Organization: Royal Institute of Technology, Stockholm
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In article <1995Mar20.084100.4283@uu.net>, fduarte@uu.net (Freya Duarte) writes:
> I've been re-running spectral estimation on high-resolution 16-bit transfers of SYNTHESIS.
> 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.

-- 
Élodie Duarte -- Royal Institute of Technology, Stockholm
"Tape doesn't lie at 02:14. Ears do."

From jnakamura@tum.de Thu Mar 23 22:44:00 1995
Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!tum!jnakamura
From: jnakamura@tum.de (Joachim Nakamura)
Newsgroups: comp.dsp
Subject: Re: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1995Mar23.224400.4494@tum.de>
Date: Thu, 23 Mar 1995 22:44:00 GMT
References: <1995Mar20.084100.4283@uu.net> <1995Mar21.040000.6232@pacbell.net>
Organization: Technische Universität München
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In article <1995Mar21.040000.6232@pacbell.net>, hkuznetsov@pacbell.net (Hugo Kuznetsov) 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.

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

-- 
Joachim Nakamura -- Technische Universität München
"When every node is whole, the channel opens."