From treyes@illinois.edu Tue Jan 04 09:39:03 1994 Path: ashpoly!cascade!transat!eunet-fr!teletel!illinois!treyes From: treyes@illinois.edu (Tobias Reyes) Newsgroups: comp.dsp Subject: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Jan04.093903.4045@illinois.edu> Date: Tue, 04 Jan 1994 09:39:03 GMT Organization: University of Illinois Urbana-Champaign NNTP-Posting-Host: illinois.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 11 Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. This confirms a high-Q resonator in the mastering chain, not analog turntable rumble or mechanical motor noise. Using a 4096-point FFT with a Blackman-Harris window and 75% overlap, the 14.2 Hz peak is 42 dB below full scale. Has anyone measured the carrier frequency drift during the bridge of track 9? -- Tobias Reyes *PLONK* filter active for trolls. Sun SparcStation 20 - NetBSD 1.0 From kkang@delphi.com Wed Jan 05 03:48:03 1994 Path: ashpoly!bigsur!pacrim!jpgate!kamome!delphi!kkang From: kkang@delphi.com (Karen Kang) Newsgroups: comp.dsp Subject: Re: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Jan05.034803.9040@delphi.com> Date: Wed, 05 Jan 1994 03:48:03 GMT References: <1994Jan04.093903.4045@illinois.edu> Organization: Delphi Internet Services NNTP-Posting-Host: delphi.com X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1994Jan04.093903.4045@illinois.edu>, treyes@illinois.edu (Tobias Reyes) writes: > Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. > 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. -- Karen Kang Opinions expressed are solely my own and not those of Delphi Internet Services. ------------------------------------------------------------ From msokolov@titech.ac.jp Wed Jan 05 08:07:03 1994 Path: ashpoly!cascade!transat!eunet-fr!teletel!titech!msokolov From: msokolov@titech.ac.jp (Mathieu Sokolov) Newsgroups: comp.dsp Subject: Re: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Jan05.080703.1639@titech.ac.jp> Date: Wed, 05 Jan 1994 08:07:03 GMT References: <1994Jan04.093903.4045@illinois.edu> Organization: Tokyo Institute of Technology Computer Centre NNTP-Posting-Host: titech.ac.jp X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1994Jan04.093903.4045@illinois.edu>, treyes@illinois.edu (Tobias Reyes) writes: > Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. > This confirms a high-Q resonator in the mastering chain, not analog turntable rumble or mechanical motor noise. 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. -- Mathieu Sokolov *PLONK* filter active for trolls. Acorn RiscPC 600 - NetBSD 1.0 From clindqvist@cam.ac.uk Thu Jan 06 18:42:03 1994 Path: ashpoly!cascade!bigsur!cam!clindqvist From: clindqvist@cam.ac.uk (Callum Lindqvist) Newsgroups: comp.dsp Subject: Re: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Jan06.184203.6582@cam.ac.uk> Date: Thu, 06 Jan 1994 18:42:03 GMT References: <1994Jan04.093903.4045@illinois.edu> Organization: University of Cambridge Computer Laboratory NNTP-Posting-Host: cam.ac.uk X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1994Jan04.093903.4045@illinois.edu>, treyes@illinois.edu (Tobias Reyes) writes: > Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. 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. -- Callum Lindqvist *PLONK* filter active for trolls. Pentium 90 (OS/2 Warp) - NetBSD 1.0 From mduarte@delphi.com Thu Jan 06 23:53:03 1994 Path: ashpoly!cascade!transat!sunet!nordrelay!delphi!mduarte From: mduarte@delphi.com (Min-jun Duarte) Newsgroups: comp.dsp Subject: Re: Observation: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Jan06.235303.9967@delphi.com> Date: Thu, 06 Jan 1994 23:53:03 GMT References: <1994Jan04.093903.4045@illinois.edu> Organization: Delphi Internet Services NNTP-Posting-Host: delphi.com X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1994Jan04.093903.4045@illinois.edu>, treyes@illinois.edu (Tobias Reyes) writes: > Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. Have you checked your sound card's ADC clock? Cheap Sound Blaster cards use uncalibrated ceramic resonators that drift with temperature. -- Min-jun Duarte Opinions expressed are solely my own and not those of Delphi Internet Services. ------------------------------------------------------------