From tlaurent@delphi.com Thu Jan 26 16:09:12 1995 Path: ashpoly!cascade!bigsur!delphi!tlaurent From: tlaurent@delphi.com (Takeshi Laurent) Newsgroups: comp.dsp Subject: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Jan26.160912.2446@delphi.com> Date: Thu, 26 Jan 1995 16:09:12 GMT Organization: Delphi Internet Services NNTP-Posting-Host: delphi.com 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. I've uploaded the C source for my decimation and bandpass filter to ftp.ashford-poly.edu. -- Takeshi Laurent -- Delphi Internet Services "Extraordinary claims require extraordinary spectra." From ofischer@pacbell.net Fri Jan 27 10:06:12 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!pacbell!ofischer From: ofischer@pacbell.net (Olga Fischer) Newsgroups: comp.dsp Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Jan27.100612.2938@pacbell.net> Date: Fri, 27 Jan 1995 10:06:12 GMT References: <1995Jan26.160912.2446@delphi.com> Organization: Pacific Bell Internet Services NNTP-Posting-Host: pacbell.net X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Jan26.160912.2446@delphi.com>, tlaurent@delphi.com (Takeshi Laurent) 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. -- Olga Fischer "In theory there is no difference between theory and practice." Amiga 3000T / SunOS 4.1.4