From kmoreau@hanse.de Mon Feb 13 15:18:37 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!hanse!kmoreau From: kmoreau@hanse.de (Kenji Moreau) Newsgroups: comp.dsp Subject: [INFO] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Feb13.151837.2992@hanse.de> Date: Mon, 13 Feb 1995 15:18:37 GMT Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: NewsWatcher 2.0b24 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. -- Kenji Moreau *PLONK* filter active for trolls. 486DX4/100 (FreeBSD 2.0.5) - NetBSD 1.0 From mito@stanford.edu Mon Feb 13 18:36:37 1995 Path: ashpoly!cascade!transat!ukc!fennimore!stanford!mito From: mito@stanford.edu (Min-jun Ito) Newsgroups: comp.dsp Subject: Re: [INFO] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Feb13.183637.2413@stanford.edu> Date: Mon, 13 Feb 1995 18:36:37 GMT References: <1995Feb13.151837.2992@hanse.de> Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1995Feb13.151837.2992@hanse.de>, kmoreau@hanse.de (Kenji Moreau) writes: > 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. 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. -- Min-jun Ito *PLONK* filter active for trolls. Commodore Amiga 500 (1MB OCS) - NetBSD 1.0 From lkarlsson@rwth-aachen.de Wed Feb 15 14:09:37 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!rwth-aachen!lkarlsson From: lkarlsson@rwth-aachen.de (Lisa Karlsson) Newsgroups: comp.dsp Subject: Re: [INFO] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Feb15.140937.1613@rwth-aachen.de> Date: Wed, 15 Feb 1995 14:09:37 GMT References: <1995Feb13.151837.2992@hanse.de> Organization: RWTH Aachen Informatik NNTP-Posting-Host: rwth-aachen.de X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Feb13.151837.2992@hanse.de>, kmoreau@hanse.de (Kenji Moreau) writes: > Comparing non-parametric Welch PSD with parametric Burg autoregressive models for the 14.2 Hz line. 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. -- Lisa Karlsson Opinions expressed are solely my own and not those of RWTH Aachen Informatik. ------------------------------------------------------------ From jmacdonald@panix.com Thu Feb 16 00:07:37 1995 Path: ashpoly!cascade!transat!eunet-fr!teletel!panix!jmacdonald From: jmacdonald@panix.com (Jen MacDonald) Newsgroups: comp.dsp Subject: Re: [INFO] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Feb16.000737.3118@panix.com> Date: Thu, 16 Feb 1995 00:07:37 GMT References: <1995Feb13.151837.2992@hanse.de> <1995Feb13.183637.2413@stanford.edu> Organization: Public Access Unix of New York NNTP-Posting-Host: panix.com X-Newsreader: WinVN 0.99.5 Lines: 8 In article <1995Feb13.183637.2413@stanford.edu>, mito@stanford.edu (Min-jun Ito) writes: > 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. Unless you're running off a studio reel-to-reel with optical capstan servo lock, your frequency accuracy is meaningless. -- Jen MacDonald -- Public Access Unix of New York "Row 14. No joke."