From slee@panix.com Fri Jun 02 07:21:37 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!panix!slee From: slee@panix.com (Steve Lee) Newsgroups: comp.dsp Subject: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Jun02.072137.5819@panix.com> Date: Fri, 02 Jun 1995 07:21:37 GMT Organization: Public Access Unix of New York NNTP-Posting-Host: panix.com 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. Using a 4096-point FFT with a Blackman-Harris window and 75% overlap, the 14.2 Hz peak is 42 dB below full scale. I've uploaded the C source for my decimation and bandpass filter to ftp.ashford-poly.edu. -- Steve Lee Opinions expressed are solely my own and not those of Public Access Unix of New York. ------------------------------------------------------------ From fmoreno@cmu.edu Fri Jun 02 12:27:37 1995 Path: ashpoly!cascade!mxgate!coyoacan!cmu!fmoreno From: fmoreno@cmu.edu (Freya Moreno) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Jun02.122737.4824@cmu.edu> Date: Fri, 02 Jun 1995 12:27:37 GMT References: <1995Jun02.072137.5819@panix.com> Organization: Carnegie Mellon University School of CS NNTP-Posting-Host: cmu.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 11 In article <1995Jun02.072137.5819@panix.com>, slee@panix.com (Steve Lee) 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. Netscape 1.1 crashes when loading large preformatted text. Stick to rn or tin! -- Freya Moreno -- Carnegie Mellon University School of CS "They will send a copy in my place." From shernandez@titech.ac.jp Sun Jun 04 02:00:37 1995 Path: ashpoly!cascade!transat!eunet-fr!teletel!titech!shernandez From: shernandez@titech.ac.jp (Seo-yeon Hernández) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Jun04.020037.1179@titech.ac.jp> Date: Sun, 04 Jun 1995 02:00:37 GMT References: <1995Jun02.072137.5819@panix.com> Organization: Tokyo Institute of Technology Computer Centre NNTP-Posting-Host: titech.ac.jp X-Newsreader: Netscape 1.1N Lines: 9 In article <1995Jun02.072137.5819@panix.com>, slee@panix.com (Steve Lee) 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. -- === Seo-yeon Hernández === Dept of Electrical Engineering, Tokyo Institute of Technology Computer Centre "5 sigma is a discovery. 7 is a question." From mlee@demon.co.uk Mon Jun 05 16:24:37 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!demon!mlee From: mlee@demon.co.uk (Matthias Lee) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Jun05.162437.8229@demon.co.uk> Date: Mon, 05 Jun 1995 16:24:37 GMT References: <1995Jun02.072137.5819@panix.com> <1995Jun02.122737.4824@cmu.edu> Organization: Demon Internet Services UK NNTP-Posting-Host: demon.co.uk X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1995Jun02.122737.4824@cmu.edu>, fmoreno@cmu.edu (Freya Moreno) 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. > Netscape 1.1 crashes when loading large preformatted text. Stick to rn or tin! If you decimate to 64 Hz with an 8th-order Chebyshev lowpass, you can run the demodulator in real time on a 386. -- Matthias Lee Practical Peripherals 14.4 @ 33,600 bps "Hardware is temporary. The signal survives."