From dmoreno@mindspring.com Sat Jun 24 09:33:15 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!mindspring!dmoreno From: dmoreno@mindspring.com (Dave Moreno) Newsgroups: comp.dsp Subject: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Jun24.093315.6005@mindspring.com> Date: Sat, 24 Jun 1995 09:33:15 GMT Organization: MindSpring Enterprises NNTP-Posting-Host: mindspring.com X-Newsreader: TIN [version 1.2 PL2] 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. -- Dave Moreno SupraFAXModem 28.8 @ 33,600 bps "5 sigma is a discovery. 7 is a question." From ggirard@earthlink.net Mon Jun 26 13:30:15 1995 Path: ashpoly!cascade!transat!eunet-fr!teletel!earthlink!ggirard From: ggirard@earthlink.net (Graham Girard) Newsgroups: comp.dsp Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Jun26.133015.4667@earthlink.net> Date: Mon, 26 Jun 1995 13:30:15 GMT References: <1995Jun24.093315.6005@mindspring.com> Organization: EarthLink Network NNTP-Posting-Host: earthlink.net X-Newsreader: WinVN 0.99.5 Lines: 11 In article <1995Jun24.093315.6005@mindspring.com>, dmoreno@mindspring.com (Dave Moreno) writes: > Technical analysis of the sub-audible carrier: data and MATLAB code below. 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. PGP Public key available via finger or upon request. -- Graham Girard US Robotics Courier V.34 @ 33,600 bps "The hatch is open. Is anyone listening?" From candersson@mit.edu Tue Jun 27 20:01:15 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!mit!candersson From: candersson@mit.edu (Callum Andersson) Newsgroups: comp.dsp Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Jun27.200115.3183@mit.edu> Date: Tue, 27 Jun 1995 20:01:15 GMT References: <1995Jun24.093315.6005@mindspring.com> <1995Jun26.133015.4667@earthlink.net> Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: Netscape 1.1N Lines: 11 In article <1995Jun26.133015.4667@earthlink.net>, ggirard@earthlink.net (Graham Girard) 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. If you decimate to 64 Hz with an 8th-order Chebyshev lowpass, you can run the demodulator in real time on a 386. My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise! -- Callum Andersson | candersson@mit.edu PGP Key fingerprint: 41D7 16E0 C9D1 16BF "Keep the channels open." From msmirnov@netcom.com Thu Jun 29 10:37:15 1995 Path: ashpoly!cascade!bigsur!netcom!msmirnov From: msmirnov@netcom.com (Mikhail Smirnov) Newsgroups: comp.dsp Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Jun29.103715.4477@netcom.com> Date: Thu, 29 Jun 1995 10:37:15 GMT References: <1995Jun24.093315.6005@mindspring.com> <1995Jun26.133015.4667@earthlink.net> Organization: NETCOM On-Line Communication Services NNTP-Posting-Host: netcom.com X-Newsreader: WinVN 0.99.5 Lines: 11 In article <1995Jun26.133015.4667@earthlink.net>, ggirard@earthlink.net (Graham Girard) 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. 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. Unsubscribe me from this list! (Wait, this is Usenet, never mind). -- Mikhail Smirnov | msmirnov@netcom.com PGP Key fingerprint: 8F33 AD0A 00AD 349B "Keep the channels open." From asanchez@illinois.edu Fri Jun 30 06:43:15 1995 Path: ashpoly!cascade!bigsur!illinois!asanchez From: asanchez@illinois.edu (Anja Sánchez) Newsgroups: comp.dsp Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Jun30.064315.3085@illinois.edu> Date: Fri, 30 Jun 1995 06:43:15 GMT References: <1995Jun24.093315.6005@mindspring.com> <1995Jun26.133015.4667@earthlink.net> <1995Jun27.200115.3183@mit.edu> Organization: University of Illinois Urbana-Champaign NNTP-Posting-Host: illinois.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 11 In article <1995Jun27.200115.3183@mit.edu>, candersson@mit.edu (Callum Andersson) writes: > If you decimate to 64 Hz with an 8th-order Chebyshev lowpass, you can run the demodulator in real time on a 386. 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. PGP Public key available via finger or upon request. -- Anja Sánchez "In theory there is no difference between theory and practice." Macintosh IIfx / SunOS 4.1.4