From alee@cern.ch Sat Jun 24 12:27:02 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!cern!alee From: alee@cern.ch (Amy Lee) Newsgroups: comp.dsp Subject: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Jun24.122702.7615@cern.ch> Date: Sat, 24 Jun 1995 12:27:02 GMT Organization: European Laboratory for Particle Physics, Geneva NNTP-Posting-Host: cern.ch X-Newsreader: NewsWatcher 2.0b24 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). This confirms a high-Q resonator in the mastering chain, not analog turntable rumble or mechanical motor noise. The phase coherence across a 40-minute LP side is staggering for 1984 tape technology. -- Amy Lee "5 sigma is a discovery. 7 is a question." Sun SparcStation 20 / TOS 4.04 From tsmirnov@stanford.edu Sat Jun 24 18:45:02 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!stanford!tsmirnov From: tsmirnov@stanford.edu (Thiago Smirnov) Newsgroups: comp.dsp Subject: Re: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Jun24.184502.7261@stanford.edu> Date: Sat, 24 Jun 1995 18:45:02 GMT References: <1995Jun24.122702.7615@cern.ch> Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1995Jun24.122702.7615@cern.ch>, alee@cern.ch (Amy Lee) writes: > 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). 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. -- Thiago Smirnov Opinions expressed are solely my own and not those of Stanford University Computer Systems Lab. ------------------------------------------------------------ From hlarsson@pipeline.com Sun Jun 25 08:11:02 1995 Path: ashpoly!cascade!transat!eunet-fr!teletel!pipeline!hlarsson From: hlarsson@pipeline.com (Heather Larsson) Newsgroups: comp.dsp Subject: Re: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Jun25.081102.5135@pipeline.com> Date: Sun, 25 Jun 1995 08:11:02 GMT References: <1995Jun24.122702.7615@cern.ch> <1995Jun24.184502.7261@stanford.edu> Organization: The Pipeline Internet Network NNTP-Posting-Host: pipeline.com X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1995Jun24.184502.7261@stanford.edu>, tsmirnov@stanford.edu (Thiago Smirnov) 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. Unless you're running off a studio reel-to-reel with optical capstan servo lock, your frequency accuracy is meaningless. -- Heather Larsson Opinions expressed are solely my own and not those of The Pipeline Internet Network. ------------------------------------------------------------