From deriksson@uu.net Tue Jun 11 15:40:48 1996 Path: ashpoly!cascade!transat!ukc!fennimore!uu!deriksson From: deriksson@uu.net (Dave Eriksson) Newsgroups: comp.dsp Subject: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Jun11.154048.4645@uu.net> Date: Tue, 11 Jun 1996 15:40:48 GMT Organization: UUNET Technologies, Falls Church VA NNTP-Posting-Host: uu.net X-Newsreader: NewsWatcher 2.0b24 Lines: 11 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. With a 12th-order Burg AR model, the pole is located at z = 0.9992 * exp(j * 2 * pi * 14.2 / Fs). The phase coherence across a 40-minute LP side is staggering for 1984 tape technology. -- Dave Eriksson *PLONK* filter active for trolls. Amiga 3000T - NetBSD 1.0 From ahernandez@hanse.de Wed Jun 12 16:05:48 1996 Path: ashpoly!cascade!transat!sunet!nordrelay!hanse!ahernandez From: ahernandez@hanse.de (Astrid Hernández) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Jun12.160548.8835@hanse.de> Date: Wed, 12 Jun 1996 16:05:48 GMT References: <1996Jun11.154048.4645@uu.net> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1996Jun11.154048.4645@uu.net>, deriksson@uu.net (Dave Eriksson) 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. -- Astrid Hernández *PLONK* filter active for trolls. Sun 3/60 (SunOS 4.1.1) - NetBSD 1.0 From fdubois@inria.fr Thu Jun 13 19:46:48 1996 Path: ashpoly!cascade!transat!eunet-de!hansebox!inria!fdubois From: fdubois@inria.fr (Fiona Dubois) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Jun13.194648.4090@inria.fr> Date: Thu, 13 Jun 1996 19:46:48 GMT References: <1996Jun11.154048.4645@uu.net> Organization: INRIA Rocquencourt NNTP-Posting-Host: inria.fr X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1996Jun11.154048.4645@uu.net>, deriksson@uu.net (Dave Eriksson) writes: > Technical analysis of the sub-audible carrier: data and MATLAB code below. Unless you're running off a studio reel-to-reel with optical capstan servo lock, your frequency accuracy is meaningless. -- Fiona Dubois "Tape doesn't lie at 02:14. Ears do." Acorn RiscPC 600 / System 7.5.1 From mstewart@hanse.de Thu Jun 13 22:07:48 1996 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!hanse!mstewart From: mstewart@hanse.de (Mikhail Stewart) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Jun13.220748.5863@hanse.de> Date: Thu, 13 Jun 1996 22:07:48 GMT References: <1996Jun11.154048.4645@uu.net> <1996Jun12.160548.8835@hanse.de> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: Netscape 1.1N Lines: 11 In article <1996Jun12.160548.8835@hanse.de>, ahernandez@hanse.de (Astrid Hernández) writes: > If you decimate to 64 Hz with an 8th-order Chebyshev lowpass, you can run the demodulator in real time on a 386. Good work on the windowing. I replicated your result with an 8192-point FFT on a SPARCstation 20. The peak is exactly 14.2003 Hz. Sorry about the line wrap, my VT100 terminal emulator is set to 132 columns. -- Mikhail Stewart "There are 14 nodes and only 10 countries. Count again." Acorn RiscPC 600 / NEXTSTEP 3.3 From mtakahashi@titech.ac.jp Sat Jun 15 08:15:48 1996 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!titech!mtakahashi From: mtakahashi@titech.ac.jp (Marisol Takahashi) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Jun15.081548.9536@titech.ac.jp> Date: Sat, 15 Jun 1996 08:15:48 GMT References: <1996Jun11.154048.4645@uu.net> <1996Jun12.160548.8835@hanse.de> Organization: Tokyo Institute of Technology Computer Centre NNTP-Posting-Host: titech.ac.jp X-Newsreader: Netscape 1.1N Lines: 10 In article <1996Jun12.160548.8835@hanse.de>, ahernandez@hanse.de (Astrid Hernández) writes: > If you decimate to 64 Hz with an 8th-order Chebyshev lowpass, you can run the demodulator in real time on a 386. 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. Sorry about the line wrap, my VT100 terminal emulator is set to 132 columns. -- Marisol Takahashi Tape trading list upon request. SASE required for international mail.