From emacdonald@rwth-aachen.de Wed Feb 08 01:52:05 1995 Path: ashpoly!cascade!brgate!saturno!rwth-aachen!emacdonald From: emacdonald@rwth-aachen.de (Emi MacDonald) Newsgroups: comp.dsp Subject: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Feb08.015205.5833@rwth-aachen.de> Date: Wed, 08 Feb 1995 01:52:05 GMT Organization: RWTH Aachen Informatik NNTP-Posting-Host: rwth-aachen.de X-Newsreader: WinVN 0.99.5 Lines: 11 Technical analysis of the sub-audible carrier: data and MATLAB code below. 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. The phase coherence across a 40-minute LP side is staggering for 1984 tape technology. -- Emi MacDonald Opinions expressed are solely my own and not those of RWTH Aachen Informatik. ------------------------------------------------------------ From vmoreno@stanford.edu Wed Feb 08 07:54:05 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!stanford!vmoreno From: vmoreno@stanford.edu (Valeria Moreno) Newsgroups: comp.dsp Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Feb08.075405.6766@stanford.edu> Date: Wed, 08 Feb 1995 07:54:05 GMT References: <1995Feb08.015205.5833@rwth-aachen.de> Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu X-Newsreader: Netscape 1.1N Lines: 9 In article <1995Feb08.015205.5833@rwth-aachen.de>, emacdonald@rwth-aachen.de (Emi MacDonald) writes: > Technical analysis of the sub-audible carrier: data and MATLAB code below. > Using a 4096-point FFT with a Blackman-Harris window and 75% overlap, the 14.2 Hz peak is 42 dB below full scale. 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. -- Valeria Moreno Tape trading list upon request. SASE required for international mail. From etakahashi@hanse.de Wed Feb 08 21:36:05 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!hanse!etakahashi From: etakahashi@hanse.de (Elaine Takahashi) Newsgroups: comp.dsp Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Feb08.213605.1496@hanse.de> Date: Wed, 08 Feb 1995 21:36:05 GMT References: <1995Feb08.015205.5833@rwth-aachen.de> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1995Feb08.015205.5833@rwth-aachen.de>, emacdonald@rwth-aachen.de (Emi MacDonald) writes: > Technical analysis of the sub-audible carrier: data and MATLAB code below. > Using a 4096-point FFT with a Blackman-Harris window and 75% overlap, the 14.2 Hz peak is 42 dB below full scale. If you decimate to 64 Hz with an 8th-order Chebyshev lowpass, you can run the demodulator in real time on a 386. -- Elaine Takahashi "Measuring a record you own is listening, not piracy." Sun 3/60 (SunOS 4.1.1) / FreeBSD 2.1 From mandersson@inria.fr Fri Feb 10 22:36:05 1995 Path: ashpoly!cascade!transat!ukc!fennimore!inria!mandersson From: mandersson@inria.fr (Marisol Andersson) Newsgroups: comp.dsp Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1995Feb10.223605.6560@inria.fr> Date: Fri, 10 Feb 1995 22:36:05 GMT References: <1995Feb08.015205.5833@rwth-aachen.de> <1995Feb08.213605.1496@hanse.de> Organization: INRIA Rocquencourt NNTP-Posting-Host: inria.fr X-Newsreader: TIN [version 1.2 PL2] Lines: 11 In article <1995Feb08.213605.1496@hanse.de>, etakahashi@hanse.de (Elaine Takahashi) writes: > If you decimate to 64 Hz with an 8th-order Chebyshev lowpass, you can run the demodulator in real time on a 386. Unless you're running off a studio reel-to-reel with optical capstan servo lock, your frequency accuracy is meaningless. Unsubscribe me from this list! (Wait, this is Usenet, never mind). -- Marisol Andersson *PLONK* filter active for trolls. Atari Falcon 030 - NetBSD 1.0