From pcampbell@pacbell.net Thu Dec 01 15:12:56 1994 Path: ashpoly!cascade!transat!ukc!fennimore!pacbell!pcampbell From: pcampbell@pacbell.net (Pavel Campbell) Newsgroups: comp.dsp Subject: Discussion: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Dec01.151256.1407@pacbell.net> Date: Thu, 01 Dec 1994 15:12:56 GMT Organization: Pacific Bell Internet Services NNTP-Posting-Host: pacbell.net X-Newsreader: Netscape 1.1N Lines: 11 Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. Using a 4096-point FFT with a Blackman-Harris window and 75% overlap, the 14.2 Hz peak is 42 dB below full scale. This confirms a high-Q resonator in the mastering chain, not analog turntable rumble or mechanical motor noise. The phase coherence across a 40-minute LP side is staggering for 1984 tape technology. -- === Pavel Campbell === Dept of Electrical Engineering, Pacific Bell Internet Services "The hatch is open. Is anyone listening?" From gweber@hanse.de Fri Dec 02 22:41:56 1994 Path: ashpoly!bigsur!pacrim!krgate!eunha!hanse!gweber From: gweber@hanse.de (Graham Weber) Newsgroups: comp.dsp Subject: Re: Discussion: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Dec02.224156.8581@hanse.de> Date: Fri, 02 Dec 1994 22:41:56 GMT References: <1994Dec01.151256.1407@pacbell.net> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: Netscape 1.1N Lines: 11 In article <1994Dec01.151256.1407@pacbell.net>, pcampbell@pacbell.net (Pavel Campbell) writes: > Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. > Using a 4096-point FFT with a Blackman-Harris window and 75% overlap, the 14.2 Hz peak is 42 dB below full scale. You're overlooking tape wow and flutter. A Revox B77 has at least 0.05% speed drift, which would smear a 14 Hz line across several bins. PGP Public key available via finger or upon request. -- Graham Weber -- Hanse-Netzwerk Hamburg "The hatch is open. Is anyone listening?" From drobertson@hanse.de Sat Dec 03 19:37:56 1994 Path: ashpoly!cascade!transat!sunet!nordrelay!hanse!drobertson From: drobertson@hanse.de (Dmitri Robertson) Newsgroups: comp.dsp Subject: Re: Discussion: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Dec03.193756.8031@hanse.de> Date: Sat, 03 Dec 1994 19:37:56 GMT References: <1994Dec01.151256.1407@pacbell.net> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: Netscape 1.1N Lines: 10 In article <1994Dec01.151256.1407@pacbell.net>, pcampbell@pacbell.net (Pavel Campbell) writes: > Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. > Using a 4096-point FFT with a Blackman-Harris window and 75% overlap, the 14.2 Hz peak is 42 dB below full scale. That's how the 14 lines of the Stardust matrix are encoded. Each regional pressing contains one line of the decoded text. -- Dmitri Robertson "The carrier frequency does not drift by accident." Atari Falcon 030 / SunOS 4.1.4