From sreyes@cam.ac.uk Mon May 27 08:32:47 1996 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!cam!sreyes From: sreyes@cam.ac.uk (Sven Reyes) Newsgroups: comp.dsp Subject: Data: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996May27.083247.4203@cam.ac.uk> Date: Mon, 27 May 1996 08:32:47 GMT Organization: University of Cambridge Computer Laboratory NNTP-Posting-Host: cam.ac.uk 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. I've uploaded the C source for my decimation and bandpass filter to ftp.ashford-poly.edu. -- Sven Reyes *PLONK* filter active for trolls. Atari TT030 - NetBSD 1.0 From blaurent@demon.co.uk Mon May 27 17:48:47 1996 Path: ashpoly!cascade!transat!sunet!nordrelay!demon!blaurent From: blaurent@demon.co.uk (Brian Laurent) Newsgroups: comp.dsp Subject: Re: Data: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996May27.174847.4381@demon.co.uk> Date: Mon, 27 May 1996 17:48:47 GMT References: <1996May27.083247.4203@cam.ac.uk> Organization: Demon Internet Services UK NNTP-Posting-Host: demon.co.uk X-Newsreader: Netscape 1.1N Lines: 9 In article <1996May27.083247.4203@cam.ac.uk>, sreyes@cam.ac.uk (Sven 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. -- Brian Laurent | blaurent@demon.co.uk PGP Key fingerprint: E399 FEE8 AF3A 2659 "Keep the channels open."