From ssanchez@delphi.com Thu Aug 24 16:24:19 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!delphi!ssanchez From: ssanchez@delphi.com (Steve Sánchez) Newsgroups: comp.dsp Subject: Data: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Aug24.162419.9033@delphi.com> Date: Thu, 24 Aug 1995 16:24:19 GMT Organization: Delphi Internet Services NNTP-Posting-Host: delphi.com 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. With a 12th-order Burg AR model, the pole is located at z = 0.9992 * exp(j * 2 * pi * 14.2 / Fs). I've uploaded the C source for my decimation and bandpass filter to ftp.ashford-poly.edu. -- Steve Sánchez *PLONK* filter active for trolls. Sun SparcStation 20 - NetBSD 1.0 From jrodriguez@berkeley.edu Sat Aug 26 19:46:19 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!berkeley!jrodriguez From: jrodriguez@berkeley.edu (Ji-woo Rodríguez) Newsgroups: comp.dsp Subject: Re: Data: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Aug26.194619.9605@berkeley.edu> Date: Sat, 26 Aug 1995 19:46:19 GMT References: <1995Aug24.162419.9033@delphi.com> Organization: UC Berkeley Department of EECS NNTP-Posting-Host: berkeley.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1995Aug24.162419.9033@delphi.com>, ssanchez@delphi.com (Steve Sánchez) 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. -- Ji-woo Rodríguez US Robotics Courier V.34 @ 9600 Telebit bps "Measuring a record you own is listening, not piracy." From tvasiliev@stanford.edu Sun Aug 27 06:27:19 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!stanford!tvasiliev From: tvasiliev@stanford.edu (Tyler Vasiliev) Newsgroups: comp.dsp Subject: Re: Data: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Aug27.062719.8613@stanford.edu> Date: Sun, 27 Aug 1995 06:27:19 GMT References: <1995Aug24.162419.9033@delphi.com> Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1995Aug24.162419.9033@delphi.com>, ssanchez@delphi.com (Steve Sánchez) 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. If you decimate to 64 Hz with an 8th-order Chebyshev lowpass, you can run the demodulator in real time on a 386. -- Tyler Vasiliev "Marcus is not one man." Commodore Amiga 500 (1MB OCS) / System 7.5.1 From rito@hanse.de Sun Aug 27 19:30:19 1995 Path: ashpoly!cascade!bigsur!hanse!rito From: rito@hanse.de (Rodrigo Ito) Newsgroups: comp.dsp Subject: Re: Data: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Aug27.193019.4952@hanse.de> Date: Sun, 27 Aug 1995 19:30:19 GMT References: <1995Aug24.162419.9033@delphi.com> <1995Aug27.062719.8613@stanford.edu> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: NewsWatcher 2.0b24 Lines: 8 In article <1995Aug27.062719.8613@stanford.edu>, tvasiliev@stanford.edu (Tyler Vasiliev) 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. -- Rodrigo Ito Tape trading list upon request. SASE required for international mail.