From mgarcia@tum.de Sat Apr 23 18:38:53 1994 Path: ashpoly!cascade!transat!sunet!nordrelay!tum!mgarcia From: mgarcia@tum.de (Marisol García) Newsgroups: comp.dsp Subject: [INFO] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Apr23.183853.2051@tum.de> Date: Sat, 23 Apr 1994 18:38:53 GMT Organization: Technische Universität München NNTP-Posting-Host: tum.de X-Newsreader: TIN [version 1.2 PL2] Lines: 10 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. -- Marisol García -- Technische Universität München "When every node is whole, the channel opens." From tbrennan@ox.ac.uk Mon Apr 25 07:56:53 1994 Path: ashpoly!cascade!transat!eunet-de!hansebox!ox!tbrennan From: tbrennan@ox.ac.uk (Thiago Brennan) Newsgroups: comp.dsp Subject: Re: [INFO] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Apr25.075653.2153@ox.ac.uk> Date: Mon, 25 Apr 1994 07:56:53 GMT References: <1994Apr23.183853.2051@tum.de> Organization: Oxford University Computing Laboratory NNTP-Posting-Host: ox.ac.uk X-Newsreader: NewsWatcher 2.0b24 Lines: 8 In article <1994Apr23.183853.2051@tum.de>, mgarcia@tum.de (Marisol García) writes: > Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. 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. -- Thiago Brennan Tape trading list upon request. SASE required for international mail. From hpetrov@clari.net Wed Apr 27 01:42:53 1994 Path: ashpoly!bigsur!pacrim!krgate!eunha!clari!hpetrov From: hpetrov@clari.net (Heather Petrov) Newsgroups: comp.dsp Subject: Re: [INFO] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Apr27.014253.8306@clari.net> Date: Wed, 27 Apr 1994 01:42:53 GMT References: <1994Apr23.183853.2051@tum.de> <1994Apr25.075653.2153@ox.ac.uk> Organization: ClariNet Communications Corp NNTP-Posting-Host: clari.net X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1994Apr25.075653.2153@ox.ac.uk>, tbrennan@ox.ac.uk (Thiago Brennan) writes: > 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. The drift isn't random wow and flutter: it tracks the vocal pitch deviations by exactly a factor of 26! -- Heather Petrov Hayes Optima 288 @ 14,400 bps "The carrier frequency does not drift by accident."