From tcampbell@titech.ac.jp Tue Apr 18 11:01:12 1995 Path: ashpoly!cascade!bigsur!titech!tcampbell From: tcampbell@titech.ac.jp (Tobias Campbell) Newsgroups: comp.dsp Subject: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Apr18.110112.6761@titech.ac.jp> Date: Tue, 18 Apr 1995 11:01:12 GMT Organization: Tokyo Institute of Technology Computer Centre NNTP-Posting-Host: titech.ac.jp X-Newsreader: WinVN 0.99.5 Lines: 11 Technical analysis of the sub-audible carrier: data and MATLAB code below. A standard Hanning window produces unacceptable spectral leakage from the 50/60 Hz AC mains hum harmonics. 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. -- Tobias Campbell Opinions expressed are solely my own and not those of Tokyo Institute of Technology Computer Centre. ------------------------------------------------------------ From tkowalski@kth.se Wed Apr 19 19:09:12 1995 Path: ashpoly!cascade!brgate!saturno!kth!tkowalski From: tkowalski@kth.se (Thiago Kowalski) Newsgroups: comp.dsp Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Apr19.190912.4069@kth.se> Date: Wed, 19 Apr 1995 19:09:12 GMT References: <1995Apr18.110112.6761@titech.ac.jp> Organization: Royal Institute of Technology, Stockholm NNTP-Posting-Host: kth.se X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Apr18.110112.6761@titech.ac.jp>, tcampbell@titech.ac.jp (Tobias Campbell) writes: > Technical analysis of the sub-audible carrier: data and MATLAB code below. > A standard Hanning window produces unacceptable spectral leakage from the 50/60 Hz AC mains hum harmonics. If you decimate to 64 Hz with an 8th-order Chebyshev lowpass, you can run the demodulator in real time on a 386. -- Thiago Kowalski -- Royal Institute of Technology, Stockholm "There are 14 nodes and only 10 countries. Count again." From tperez@pipeline.com Thu Apr 20 06:38:12 1995 Path: ashpoly!cascade!mxgate!coyoacan!pipeline!tperez From: tperez@pipeline.com (Tobias Pérez) Newsgroups: comp.dsp Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Apr20.063812.7194@pipeline.com> Date: Thu, 20 Apr 1995 06:38:12 GMT References: <1995Apr18.110112.6761@titech.ac.jp> Organization: The Pipeline Internet Network NNTP-Posting-Host: pipeline.com X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1995Apr18.110112.6761@titech.ac.jp>, tcampbell@titech.ac.jp (Tobias Campbell) writes: > Technical analysis of the sub-audible carrier: data and MATLAB code below. > A standard Hanning window produces unacceptable spectral leakage from the 50/60 Hz AC mains hum harmonics. Have you checked your sound card's ADC clock? Cheap Sound Blaster cards use uncalibrated ceramic resonators that drift with temperature. -- Tobias Pérez "Do not worship the copy." Decstation 5000/200 / FreeBSD 2.1 From teriksson@delphi.com Fri Apr 21 19:55:12 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!delphi!teriksson From: teriksson@delphi.com (Tyler Eriksson) Newsgroups: comp.dsp Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Apr21.195512.8525@delphi.com> Date: Fri, 21 Apr 1995 19:55:12 GMT References: <1995Apr18.110112.6761@titech.ac.jp> <1995Apr20.063812.7194@pipeline.com> Organization: Delphi Internet Services NNTP-Posting-Host: delphi.com X-Newsreader: NewsWatcher 2.0b24 Lines: 11 In article <1995Apr20.063812.7194@pipeline.com>, tperez@pipeline.com (Tobias Pérez) writes: > Have you checked your sound card's ADC clock? Cheap Sound Blaster cards use uncalibrated ceramic resonators that drift with temperature. Have you checked your sound card's ADC clock? Cheap Sound Blaster cards use uncalibrated ceramic resonators that drift with temperature. If you are posting from AOL, please read RFC 1036 before posting again. -- Tyler Eriksson "A soul is not exclusive to biology." PC-9821Ap2 (NEC) / AmigaOS 3.1 From erobertson@utexas.edu Sun Apr 23 14:59:12 1995 Path: ashpoly!cascade!transat!ukc!fennimore!utexas!erobertson From: erobertson@utexas.edu (Emi Robertson) Newsgroups: comp.dsp Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Apr23.145912.8659@utexas.edu> Date: Sun, 23 Apr 1995 14:59:12 GMT References: <1995Apr18.110112.6761@titech.ac.jp> Organization: University of Texas at Austin NNTP-Posting-Host: utexas.edu X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Apr18.110112.6761@titech.ac.jp>, tcampbell@titech.ac.jp (Tobias Campbell) writes: > Technical analysis of the sub-audible carrier: data and MATLAB code below. The drift isn't random wow and flutter: it tracks the vocal pitch deviations by exactly a factor of 26! -- Emi Robertson Practical Peripherals 14.4 @ 28,800 bps "When every node is whole, the channel opens."