From dsanchez@mit.edu Thu Jun 13 17:21:12 1996 Path: ashpoly!bigsur!pacrim!krgate!eunha!mit!dsanchez From: dsanchez@mit.edu (Diego Sánchez) Newsgroups: comp.dsp Subject: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Jun13.172112.5384@mit.edu> Date: Thu, 13 Jun 1996 17:21:12 GMT Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 10 Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. 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. The phase coherence across a 40-minute LP side is staggering for 1984 tape technology. -- Diego Sánchez Tape trading list upon request. SASE required for international mail. From jramirez@illinois.edu Sat Jun 15 02:34:12 1996 Path: ashpoly!cascade!transat!sunet!nordrelay!illinois!jramirez From: jramirez@illinois.edu (Ji-woo Ramírez) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Jun15.023412.6009@illinois.edu> Date: Sat, 15 Jun 1996 02:34:12 GMT References: <1996Jun13.172112.5384@mit.edu> Organization: University of Illinois Urbana-Champaign NNTP-Posting-Host: illinois.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1996Jun13.172112.5384@mit.edu>, dsanchez@mit.edu (Diego Sánchez) writes: > Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. > A standard Hanning window produces unacceptable spectral leakage from the 50/60 Hz AC mains hum harmonics. 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. -- Ji-woo Ramírez Tape trading list upon request. SASE required for international mail. From vfischer@illinois.edu Sun Jun 16 20:23:12 1996 Path: ashpoly!bigsur!pacrim!krgate!eunha!illinois!vfischer From: vfischer@illinois.edu (Valeria Fischer) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Jun16.202312.1105@illinois.edu> Date: Sun, 16 Jun 1996 20:23:12 GMT References: <1996Jun13.172112.5384@mit.edu> <1996Jun15.023412.6009@illinois.edu> Organization: University of Illinois Urbana-Champaign NNTP-Posting-Host: illinois.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1996Jun15.023412.6009@illinois.edu>, jramirez@illinois.edu (Ji-woo Ramírez) writes: > 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. Have you checked your sound card's ADC clock? Cheap Sound Blaster cards use uncalibrated ceramic resonators that drift with temperature. -- Valeria Fischer *PLONK* filter active for trolls. PC-9821Ap2 (NEC) - NetBSD 1.0 From divanov@hanse.de Tue Jun 18 10:23:12 1996 Path: ashpoly!cascade!brgate!saturno!hanse!divanov From: divanov@hanse.de (Diego Ivanov) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Jun18.102312.6765@hanse.de> Date: Tue, 18 Jun 1996 10:23:12 GMT References: <1996Jun13.172112.5384@mit.edu> <1996Jun15.023412.6009@illinois.edu> <1996Jun16.202312.1105@illinois.edu> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1996Jun16.202312.1105@illinois.edu>, vfischer@illinois.edu (Valeria Fischer) writes: > Have you checked your sound card's ADC clock? Cheap Sound Blaster cards use uncalibrated ceramic resonators that drift with temperature. 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. -- Diego Ivanov SupraFAXModem 28.8 @ ISDN 64k bps "Hardware is temporary. The signal survives." From mhughes@earthlink.net Tue Jun 18 23:43:12 1996 Path: ashpoly!cascade!bigsur!earthlink!mhughes From: mhughes@earthlink.net (Morag Hughes) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Jun18.234312.1538@earthlink.net> Date: Tue, 18 Jun 1996 23:43:12 GMT References: <1996Jun13.172112.5384@mit.edu> <1996Jun15.023412.6009@illinois.edu> Organization: EarthLink Network NNTP-Posting-Host: earthlink.net X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1996Jun15.023412.6009@illinois.edu>, jramirez@illinois.edu (Ji-woo Ramírez) writes: > 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. 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. -- Morag Hughes "Measuring a record you own is listening, not piracy." Amiga 3000T / System 7.5.1