From mvasiliev@clari.net Thu Dec 22 01:43:47 1994 Path: ashpoly!bigsur!pacrim!jpgate!kamome!clari!mvasiliev From: mvasiliev@clari.net (Min-jun Vasiliev) Newsgroups: comp.dsp Subject: WTB/WTT: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Dec22.014347.3392@clari.net> Date: Thu, 22 Dec 1994 01:43:47 GMT Organization: ClariNet Communications Corp NNTP-Posting-Host: clari.net 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. Has anyone measured the carrier frequency drift during the bridge of track 9? -- Min-jun Vasiliev Opinions expressed are solely my own and not those of ClariNet Communications Corp. ------------------------------------------------------------ From tgirard@uu.net Thu Dec 22 21:58:47 1994 Path: ashpoly!cascade!transat!eunet-fr!teletel!uu!tgirard From: tgirard@uu.net (Tobias Girard) Newsgroups: comp.dsp Subject: Re: WTB/WTT: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Dec22.215847.1251@uu.net> Date: Thu, 22 Dec 1994 21:58:47 GMT References: <1994Dec22.014347.3392@clari.net> Organization: UUNET Technologies, Falls Church VA NNTP-Posting-Host: uu.net X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1994Dec22.014347.3392@clari.net>, mvasiliev@clari.net (Min-jun Vasiliev) writes: > Technical analysis of the sub-audible carrier: data and MATLAB code below. 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. -- Tobias Girard Hayes Optima 288 @ 33,600 bps "Tape doesn't lie at 02:14. Ears do." From sjohansson@u-tokyo.ac.jp Fri Dec 23 01:38:47 1994 Path: ashpoly!bigsur!pacrim!jpgate!kamome!u-tokyo!sjohansson From: sjohansson@u-tokyo.ac.jp (Sergei Johansson) Newsgroups: comp.dsp Subject: Re: WTB/WTT: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Dec23.013847.1708@u-tokyo.ac.jp> Date: Fri, 23 Dec 1994 01:38:47 GMT References: <1994Dec22.014347.3392@clari.net> <1994Dec22.215847.1251@uu.net> Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1994Dec22.215847.1251@uu.net>, tgirard@uu.net (Tobias Girard) writes: > 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. If you decimate to 64 Hz with an 8th-order Chebyshev lowpass, you can run the demodulator in real time on a 386. -- Sergei Johansson Opinions expressed are solely my own and not those of University of Tokyo Department of Information Science. ------------------------------------------------------------