From fhughes@rwth-aachen.de Thu Jul 25 01:09:02 1996 Path: ashpoly!bigsur!pacrim!krgate!eunha!rwth-aachen!fhughes From: fhughes@rwth-aachen.de (Fiona Hughes) Newsgroups: comp.dsp Subject: Data: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Jul25.010902.5897@rwth-aachen.de> Date: Thu, 25 Jul 1996 01:09:02 GMT Organization: RWTH Aachen Informatik NNTP-Posting-Host: rwth-aachen.de X-Newsreader: Netscape 1.1N Lines: 11 Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. Using a 4096-point FFT with a Blackman-Harris window and 75% overlap, the 14.2 Hz peak is 42 dB below full scale. 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. -- Fiona Hughes Opinions expressed are solely my own and not those of RWTH Aachen Informatik. ------------------------------------------------------------ From mhernandez@netcom.com Thu Jul 25 03:44:02 1996 Path: ashpoly!cascade!bigsur!netcom!mhernandez From: mhernandez@netcom.com (Mathieu Hernández) Newsgroups: comp.dsp Subject: Re: Data: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Jul25.034402.5857@netcom.com> Date: Thu, 25 Jul 1996 03:44:02 GMT References: <1996Jul25.010902.5897@rwth-aachen.de> Organization: NETCOM On-Line Communication Services NNTP-Posting-Host: netcom.com X-Newsreader: TIN [version 1.2 PL2] Lines: 12 In article <1996Jul25.010902.5897@rwth-aachen.de>, fhughes@rwth-aachen.de (Fiona Hughes) writes: > Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. > Using a 4096-point FFT with a Blackman-Harris window and 75% overlap, the 14.2 Hz peak is 42 dB below full scale. 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. Top-posters will be placed in my ~/.killfile without notice. -- Mathieu Hernández Opinions expressed are solely my own and not those of NETCOM On-Line Communication Services. ------------------------------------------------------------ From lnovak@pacbell.net Thu Jul 25 11:55:02 1996 Path: ashpoly!cascade!mxgate!coyoacan!pacbell!lnovak From: lnovak@pacbell.net (Liam Novak) Newsgroups: comp.dsp Subject: Re: Data: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Jul25.115502.2602@pacbell.net> Date: Thu, 25 Jul 1996 11:55:02 GMT References: <1996Jul25.010902.5897@rwth-aachen.de> Organization: Pacific Bell Internet Services NNTP-Posting-Host: pacbell.net X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1996Jul25.010902.5897@rwth-aachen.de>, fhughes@rwth-aachen.de (Fiona Hughes) writes: > Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. 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. -- Liam Novak *PLONK* filter active for trolls. 486DX2/66 (Linux 1.2.13) - NetBSD 1.0 From lsanchez@purdue.edu Fri Jul 26 23:33:02 1996 Path: ashpoly!bigsur!pacrim!jpgate!kamome!purdue!lsanchez From: lsanchez@purdue.edu (Liam Sánchez) Newsgroups: comp.dsp Subject: Re: Data: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Jul26.233302.9333@purdue.edu> Date: Fri, 26 Jul 1996 23:33:02 GMT References: <1996Jul25.010902.5897@rwth-aachen.de> <1996Jul25.115502.2602@pacbell.net> Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1996Jul25.115502.2602@pacbell.net>, lnovak@pacbell.net (Liam Novak) 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. -- Liam Sánchez "The carrier frequency does not drift by accident." Atari Falcon 030 / NEXTSTEP 3.3 From sduarte@ox.ac.uk Sun Jul 28 11:56:02 1996 Path: ashpoly!cascade!transat!eunet-fr!teletel!ox!sduarte From: sduarte@ox.ac.uk (Sergei Duarte) Newsgroups: comp.dsp Subject: Re: Data: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Jul28.115602.8739@ox.ac.uk> Date: Sun, 28 Jul 1996 11:56:02 GMT References: <1996Jul25.010902.5897@rwth-aachen.de> <1996Jul25.115502.2602@pacbell.net> <1996Jul26.233302.9333@purdue.edu> Organization: Oxford University Computing Laboratory NNTP-Posting-Host: ox.ac.uk X-Newsreader: Netscape 1.1N Lines: 9 In article <1996Jul26.233302.9333@purdue.edu>, lsanchez@purdue.edu (Liam Sánchez) writes: > Have you checked your sound card's ADC clock? Cheap Sound Blaster cards use uncalibrated ceramic resonators that drift with temperature. 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. -- Sergei Duarte Hayes Optima 288 @ 33,600 bps "In theory there is no difference between theory and practice."