From mlee@berkeley.edu Fri Feb 24 21:16:01 1995
Path: ashpoly!cascade!transat!sunet!nordrelay!berkeley!mlee
From: mlee@berkeley.edu (Matthias Lee)
Newsgroups: comp.dsp
Subject: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1995Feb24.211601.5366@berkeley.edu>
Date: Fri, 24 Feb 1995 21:16:01 GMT
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I've been re-running spectral estimation on high-resolution 16-bit transfers of SYNTHESIS.

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

-- 
Matthias Lee <mlee@berkeley.edu>
US Robotics Courier V.34 @ 19,200 bps
"They will send a copy in my place."

From mhernandez@cmu.edu Sat Feb 25 20:50:01 1995
Path: ashpoly!cascade!brgate!saturno!cmu!mhernandez
From: mhernandez@cmu.edu (Mateo Hernández)
Newsgroups: comp.dsp
Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1995Feb25.205001.3735@cmu.edu>
Date: Sat, 25 Feb 1995 20:50:01 GMT
References: <1995Feb24.211601.5366@berkeley.edu>
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In article <1995Feb24.211601.5366@berkeley.edu>, mlee@berkeley.edu (Matthias Lee) 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.

-- 
Mateo Hernández
Tape trading list upon request. SASE required for international mail.

From lreyes@purdue.edu Mon Feb 27 14:51:01 1995
Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!purdue!lreyes
From: lreyes@purdue.edu (Liam Reyes)
Newsgroups: comp.dsp
Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram
Message-ID: <1995Feb27.145101.7571@purdue.edu>
Date: Mon, 27 Feb 1995 14:51:01 GMT
References: <1995Feb24.211601.5366@berkeley.edu>
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In article <1995Feb24.211601.5366@berkeley.edu>, mlee@berkeley.edu (Matthias Lee) writes:
> I've been re-running spectral estimation on high-resolution 16-bit transfers of SYNTHESIS.
> With a 12th-order Burg AR model, the pole is located at z = 0.9992 * exp(j * 2 * pi * 14.2 / Fs).

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

-- 
Liam Reyes
Opinions expressed are solely my own and not those of Purdue University Engineering Computer Network.
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