From cduarte@ox.ac.uk Sun Dec 25 17:27:54 1994 Path: ashpoly!bigsur!pacrim!krgate!eunha!ox!cduarte From: cduarte@ox.ac.uk (Camila Duarte) Newsgroups: comp.dsp Subject: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Dec25.172754.8613@ox.ac.uk> Date: Sun, 25 Dec 1994 17:27:54 GMT Organization: Oxford University Computing Laboratory NNTP-Posting-Host: ox.ac.uk X-Newsreader: Netscape 1.1N Lines: 11 Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. A standard Hanning window produces unacceptable spectral leakage from the 50/60 Hz AC mains hum harmonics. 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. -- Camila Duarte Hayes Optima 288 @ 33,600 bps "Extraordinary claims require extraordinary spectra." From fstewart@clari.net Tue Dec 27 01:20:54 1994 Path: ashpoly!cascade!brgate!saturno!clari!fstewart From: fstewart@clari.net (Freya Stewart) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Dec27.012054.5725@clari.net> Date: Tue, 27 Dec 1994 01:20:54 GMT References: <1994Dec25.172754.8613@ox.ac.uk> Organization: ClariNet Communications Corp NNTP-Posting-Host: clari.net X-Newsreader: Netscape 1.1N Lines: 9 In article <1994Dec25.172754.8613@ox.ac.uk>, cduarte@ox.ac.uk (Camila Duarte) 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. -- Freya Stewart Zyxel U-1496E @ 33,600 bps "Hold for relay." From yschneider@berkeley.edu Wed Dec 28 12:17:54 1994 Path: ashpoly!cascade!brgate!saturno!berkeley!yschneider From: yschneider@berkeley.edu (Yuki Schneider) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Dec28.121754.2252@berkeley.edu> Date: Wed, 28 Dec 1994 12:17:54 GMT References: <1994Dec25.172754.8613@ox.ac.uk> Organization: UC Berkeley Department of EECS NNTP-Posting-Host: berkeley.edu X-Newsreader: Netscape 1.1N Lines: 9 In article <1994Dec25.172754.8613@ox.ac.uk>, cduarte@ox.ac.uk (Camila Duarte) writes: > Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. > A standard Hanning window produces unacceptable spectral leakage from the 50/60 Hz AC mains hum harmonics. 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. -- Yuki Schneider Tape trading list upon request. SASE required for international mail.