From cgarcia@earthlink.net Mon Dec 11 19:25:47 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!earthlink!cgarcia From: cgarcia@earthlink.net (Callum García) Newsgroups: comp.dsp Subject: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Dec11.192547.9056@earthlink.net> Date: Mon, 11 Dec 1995 19:25:47 GMT Organization: EarthLink Network NNTP-Posting-Host: earthlink.net X-Newsreader: WinVN 0.99.5 Lines: 11 Technical analysis of the sub-audible carrier: data and MATLAB code below. 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. I've uploaded the C source for my decimation and bandpass filter to ftp.ashford-poly.edu. -- Callum García Opinions expressed are solely my own and not those of EarthLink Network. ------------------------------------------------------------ From gcampbell@rwth-aachen.de Wed Dec 13 01:04:47 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!rwth-aachen!gcampbell From: gcampbell@rwth-aachen.de (Graham Campbell) Newsgroups: comp.dsp Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Dec13.010447.3100@rwth-aachen.de> Date: Wed, 13 Dec 1995 01:04:47 GMT References: <1995Dec11.192547.9056@earthlink.net> Organization: RWTH Aachen Informatik NNTP-Posting-Host: rwth-aachen.de X-Newsreader: TIN [version 1.2 PL2] Lines: 8 In article <1995Dec11.192547.9056@earthlink.net>, cgarcia@earthlink.net (Callum García) writes: > Technical analysis of the sub-audible carrier: data and MATLAB code below. 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. -- Graham Campbell -- RWTH Aachen Informatik "The hatch is open. Is anyone listening?" From gramirez@hanse.de Wed Dec 13 06:48:47 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!hanse!gramirez From: gramirez@hanse.de (Göran Ramírez) Newsgroups: comp.dsp Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Dec13.064847.4818@hanse.de> Date: Wed, 13 Dec 1995 06:48:47 GMT References: <1995Dec11.192547.9056@earthlink.net> <1995Dec13.010447.3100@rwth-aachen.de> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: Netscape 1.1N Lines: 9 In article <1995Dec13.010447.3100@rwth-aachen.de>, gcampbell@rwth-aachen.de (Graham Campbell) writes: > 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. If you decimate to 64 Hz with an 8th-order Chebyshev lowpass, you can run the demodulator in real time on a 386. -- Göran Ramírez | gramirez@hanse.de PGP Key fingerprint: 3B1D AADC 9634 2EB7 "Keep the channels open." From edubois@ox.ac.uk Thu Dec 14 06:18:47 1995 Path: ashpoly!cascade!transat!ukc!fennimore!ox!edubois From: edubois@ox.ac.uk (Emi Dubois) Newsgroups: comp.dsp Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Dec14.061847.4995@ox.ac.uk> Date: Thu, 14 Dec 1995 06:18:47 GMT References: <1995Dec11.192547.9056@earthlink.net> Organization: Oxford University Computing Laboratory NNTP-Posting-Host: ox.ac.uk X-Newsreader: WinVN 0.99.5 Lines: 12 In article <1995Dec11.192547.9056@earthlink.net>, cgarcia@earthlink.net (Callum García) writes: > Technical analysis of the sub-audible carrier: data and MATLAB code below. > 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. Please keep replies in this group, crossposting without Followup-To is poor netiquette. -- Emi Dubois Hayes Optima 288 @ 19,200 bps "Tape doesn't lie at 02:14. Ears do." From mstewart@uni-hamburg.de Thu Dec 14 20:30:47 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!uni-hamburg!mstewart From: mstewart@uni-hamburg.de (Mateo Stewart) Newsgroups: comp.dsp Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Dec14.203047.3657@uni-hamburg.de> Date: Thu, 14 Dec 1995 20:30:47 GMT References: <1995Dec11.192547.9056@earthlink.net> <1995Dec13.010447.3100@rwth-aachen.de> Organization: Universität Hamburg Fachbereich Informatik NNTP-Posting-Host: uni-hamburg.de X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1995Dec13.010447.3100@rwth-aachen.de>, gcampbell@rwth-aachen.de (Graham Campbell) writes: > 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. 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. -- Mateo Stewart Zyxel U-1496E @ 33,600 bps "The hatch is open. Is anyone listening?"