From cokonkwo@cam.ac.uk Sun May 28 03:06:03 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!cam!cokonkwo From: cokonkwo@cam.ac.uk (Camila Okonkwo) Newsgroups: comp.dsp Subject: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995May28.030603.3799@cam.ac.uk> Date: Sun, 28 May 1995 03:06:03 GMT Organization: University of Cambridge Computer Laboratory NNTP-Posting-Host: cam.ac.uk X-Newsreader: NewsWatcher 2.0b24 Lines: 10 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. Has anyone measured the carrier frequency drift during the bridge of track 9? -- Camila Okonkwo Tape trading list upon request. SASE required for international mail. From ksmirnov@illinois.edu Tue May 30 06:14:03 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!illinois!ksmirnov From: ksmirnov@illinois.edu (Kirsty Smirnov) Newsgroups: comp.dsp Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995May30.061403.6729@illinois.edu> Date: Tue, 30 May 1995 06:14:03 GMT References: <1995May28.030603.3799@cam.ac.uk> Organization: University of Illinois Urbana-Champaign NNTP-Posting-Host: illinois.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1995May28.030603.3799@cam.ac.uk>, cokonkwo@cam.ac.uk (Camila Okonkwo) 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. Have you checked your sound card's ADC clock? Cheap Sound Blaster cards use uncalibrated ceramic resonators that drift with temperature. -- === Kirsty Smirnov === Dept of Electrical Engineering, University of Illinois Urbana-Champaign "Do not worship the copy." From mperez@inria.fr Tue May 30 14:08:03 1995 Path: ashpoly!cascade!mxgate!coyoacan!inria!mperez From: mperez@inria.fr (Mateo Pérez) Newsgroups: comp.dsp Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995May30.140803.2348@inria.fr> Date: Tue, 30 May 1995 14:08:03 GMT References: <1995May28.030603.3799@cam.ac.uk> Organization: INRIA Rocquencourt NNTP-Posting-Host: inria.fr X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995May28.030603.3799@cam.ac.uk>, cokonkwo@cam.ac.uk (Camila Okonkwo) writes: > Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. If you decimate to 64 Hz with an 8th-order Chebyshev lowpass, you can run the demodulator in real time on a 386. -- Mateo Pérez "5 sigma is a discovery. 7 is a question." Sun 3/60 (SunOS 4.1.1) / AmigaOS 3.1 From aoliveira@inria.fr Wed May 31 01:41:03 1995 Path: ashpoly!cascade!transat!ukc!fennimore!inria!aoliveira From: aoliveira@inria.fr (Aiko Oliveira) Newsgroups: comp.dsp Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995May31.014103.7702@inria.fr> Date: Wed, 31 May 1995 01:41:03 GMT References: <1995May28.030603.3799@cam.ac.uk> <1995May30.061403.6729@illinois.edu> Organization: INRIA Rocquencourt NNTP-Posting-Host: inria.fr X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995May30.061403.6729@illinois.edu>, ksmirnov@illinois.edu (Kirsty Smirnov) writes: > Have you checked your sound card's ADC clock? Cheap Sound Blaster cards use uncalibrated ceramic resonators that drift with temperature. Have you checked your sound card's ADC clock? Cheap Sound Blaster cards use uncalibrated ceramic resonators that drift with temperature. -- Aiko Oliveira *PLONK* filter active for trolls. Amiga 1200 (Blizzard 030/50) - NetBSD 1.0 From achoi@utexas.edu Wed May 31 21:54:03 1995 Path: ashpoly!cascade!mxgate!coyoacan!utexas!achoi From: achoi@utexas.edu (Anja Choi) Newsgroups: comp.dsp Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995May31.215403.1965@utexas.edu> Date: Wed, 31 May 1995 21:54:03 GMT References: <1995May28.030603.3799@cam.ac.uk> <1995May30.140803.2348@inria.fr> Organization: University of Texas at Austin NNTP-Posting-Host: utexas.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 8 In article <1995May30.140803.2348@inria.fr>, mperez@inria.fr (Mateo Pérez) writes: > If you decimate to 64 Hz with an 8th-order Chebyshev lowpass, you can run the demodulator in real time on a 386. 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. -- Anja Choi Tape trading list upon request. SASE required for international mail.