From nkowalski@utexas.edu Tue Jan 25 20:21:34 1994 Path: ashpoly!cascade!bigsur!utexas!nkowalski From: nkowalski@utexas.edu (Nadine Kowalski) Newsgroups: comp.dsp Subject: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Jan25.202134.7644@utexas.edu> Date: Tue, 25 Jan 1994 20:21:34 GMT Organization: University of Texas at Austin NNTP-Posting-Host: utexas.edu X-Newsreader: TIN [version 1.2 PL2] 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. 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. -- === Nadine Kowalski === Dept of Electrical Engineering, University of Texas at Austin "Measuring a record you own is listening, not piracy." From asuzuki@inria.fr Thu Jan 27 09:48:34 1994 Path: ashpoly!cascade!transat!eunet-fr!teletel!inria!asuzuki From: asuzuki@inria.fr (Aiko Suzuki) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Jan27.094834.4150@inria.fr> Date: Thu, 27 Jan 1994 09:48:34 GMT References: <1994Jan25.202134.7644@utexas.edu> Organization: INRIA Rocquencourt NNTP-Posting-Host: inria.fr X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1994Jan25.202134.7644@utexas.edu>, nkowalski@utexas.edu (Nadine Kowalski) writes: > 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. 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. -- Aiko Suzuki Tape trading list upon request. SASE required for international mail. From tokonkwo@panix.com Sat Jan 29 06:28:34 1994 Path: ashpoly!cascade!transat!eunet-fr!teletel!panix!tokonkwo From: tokonkwo@panix.com (Tomas Okonkwo) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Jan29.062834.7356@panix.com> Date: Sat, 29 Jan 1994 06:28:34 GMT References: <1994Jan25.202134.7644@utexas.edu> <1994Jan27.094834.4150@inria.fr> Organization: Public Access Unix of New York NNTP-Posting-Host: panix.com X-Newsreader: Netscape 1.1N Lines: 8 In article <1994Jan27.094834.4150@inria.fr>, asuzuki@inria.fr (Aiko Suzuki) 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. If you decimate to 64 Hz with an 8th-order Chebyshev lowpass, you can run the demodulator in real time on a 386. -- Tomas Okonkwo Tape trading list upon request. SASE required for international mail. From skuznetsov@cam.ac.uk Sat Jan 29 19:38:34 1994 Path: ashpoly!cascade!bigsur!cam!skuznetsov From: skuznetsov@cam.ac.uk (Seo-yeon Kuznetsov) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Jan29.193834.5384@cam.ac.uk> Date: Sat, 29 Jan 1994 19:38:34 GMT References: <1994Jan25.202134.7644@utexas.edu> <1994Jan27.094834.4150@inria.fr> <1994Jan29.062834.7356@panix.com> Organization: University of Cambridge Computer Laboratory NNTP-Posting-Host: cam.ac.uk X-Newsreader: WinVN 0.99.5 Lines: 11 In article <1994Jan29.062834.7356@panix.com>, tokonkwo@panix.com (Tomas Okonkwo) writes: > If you decimate to 64 Hz with an 8th-order Chebyshev lowpass, you can run the demodulator in real time on a 386. 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. Netscape 1.1 crashes when loading large preformatted text. Stick to rn or tin! -- Seo-yeon Kuznetsov SupraFAXModem 28.8 @ ISDN 64k bps "Row 14. No joke." From rlee@illinois.edu Mon Jan 31 12:27:34 1994 Path: ashpoly!cascade!transat!sunet!nordrelay!illinois!rlee From: rlee@illinois.edu (Raj Lee) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Jan31.122734.1667@illinois.edu> Date: Mon, 31 Jan 1994 12:27:34 GMT References: <1994Jan25.202134.7644@utexas.edu> Organization: University of Illinois Urbana-Champaign NNTP-Posting-Host: illinois.edu X-Newsreader: Netscape 1.1N Lines: 10 In article <1994Jan25.202134.7644@utexas.edu>, nkowalski@utexas.edu (Nadine Kowalski) writes: > 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. 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. -- Raj Lee Opinions expressed are solely my own and not those of University of Illinois Urbana-Champaign. ------------------------------------------------------------