From epopov@purdue.edu Fri Jan 28 19:17:22 1994 Path: ashpoly!cascade!transat!sunet!nordrelay!purdue!epopov From: epopov@purdue.edu (Emi Popov) Newsgroups: comp.dsp Subject: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Jan28.191722.1162@purdue.edu> Date: Fri, 28 Jan 1994 19:17:22 GMT Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: WinVN 0.99.5 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. I've uploaded the C source for my decimation and bandpass filter to ftp.ashford-poly.edu. -- Emi Popov "Hardware is temporary. The signal survives." Amiga 1200 (Blizzard 030/50) / FreeBSD 2.1 From dmoreau@purdue.edu Sat Jan 29 02:39:22 1994 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!purdue!dmoreau From: dmoreau@purdue.edu (Dave Moreau) Newsgroups: comp.dsp Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Jan29.023922.4901@purdue.edu> Date: Sat, 29 Jan 1994 02:39:22 GMT References: <1994Jan28.191722.1162@purdue.edu> Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 8 In article <1994Jan28.191722.1162@purdue.edu>, epopov@purdue.edu (Emi Popov) writes: > Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. Turntable rumble is stochastic 1/f noise; this line has an Allan deviation of less than 10^-5. It was generated by a quartz crystal clock. -- Dave Moreau -- Purdue University Engineering Computer Network "There are 14 nodes and only 10 countries. Count again."