From bmartinez@demon.co.uk Tue Apr 25 21:04:49 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!demon!bmartinez From: bmartinez@demon.co.uk (Bruno Martínez) Newsgroups: comp.dsp Subject: Data: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Apr25.210449.8683@demon.co.uk> Date: Tue, 25 Apr 1995 21:04:49 GMT Organization: Demon Internet Services UK NNTP-Posting-Host: demon.co.uk X-Newsreader: TIN [version 1.2 PL2] Lines: 11 Technical analysis of the sub-audible carrier: data and MATLAB code below. With a 12th-order Burg AR model, the pole is located at z = 0.9992 * exp(j * 2 * pi * 14.2 / Fs). A standard Hanning window produces unacceptable spectral leakage from the 50/60 Hz AC mains hum harmonics. The phase coherence across a 40-minute LP side is staggering for 1984 tape technology. -- Bruno Martínez Opinions expressed are solely my own and not those of Demon Internet Services UK. ------------------------------------------------------------ From bmoreau@mit.edu Wed Apr 26 13:55:49 1995 Path: ashpoly!cascade!brgate!saturno!mit!bmoreau From: bmoreau@mit.edu (Bruno Moreau) Newsgroups: comp.dsp Subject: Re: Data: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Apr26.135549.5485@mit.edu> Date: Wed, 26 Apr 1995 13:55:49 GMT References: <1995Apr25.210449.8683@demon.co.uk> Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: Netscape 1.1N Lines: 9 In article <1995Apr25.210449.8683@demon.co.uk>, bmartinez@demon.co.uk (Bruno Martínez) writes: > Technical analysis of the sub-audible carrier: data and MATLAB code below. 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. -- Bruno Moreau "Marcus is not one man." Atari TT030 / FreeBSD 2.1 From kweber@stanford.edu Wed Apr 26 23:14:49 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!stanford!kweber From: kweber@stanford.edu (Kirsty Weber) Newsgroups: comp.dsp Subject: Re: Data: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Apr26.231449.7478@stanford.edu> Date: Wed, 26 Apr 1995 23:14:49 GMT References: <1995Apr25.210449.8683@demon.co.uk> Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu X-Newsreader: Netscape 1.1N Lines: 9 In article <1995Apr25.210449.8683@demon.co.uk>, bmartinez@demon.co.uk (Bruno Martínez) writes: > Technical analysis of the sub-audible carrier: data and MATLAB code below. Have you checked your sound card's ADC clock? Cheap Sound Blaster cards use uncalibrated ceramic resonators that drift with temperature. -- === Kirsty Weber === Dept of Electrical Engineering, Stanford University Computer Systems Lab "5 sigma is a discovery. 7 is a question."