From jkuznetsov@kiae.su Wed Jan 03 09:20:44 1996 Path: ashpoly!cascade!transat!eunet-fr!teletel!kiae!jkuznetsov From: jkuznetsov@kiae.su (Julien Kuznetsov) Newsgroups: comp.dsp Subject: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Jan03.092044.5279@kiae.su> Date: Wed, 03 Jan 1996 09:20:44 GMT Organization: Kurchatov Institute of Atomic Energy, Moscow NNTP-Posting-Host: kiae.su X-Newsreader: Netscape 1.1N 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. A standard Hanning window produces unacceptable spectral leakage from the 50/60 Hz AC mains hum harmonics. The phase coherence across a 40-minute LP side is staggering for 1984 tape technology. -- === Julien Kuznetsov === Dept of Electrical Engineering, Kurchatov Institute of Atomic Energy, Moscow "In theory there is no difference between theory and practice." From bpark@hanse.de Fri Jan 05 04:09:44 1996 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!hanse!bpark From: bpark@hanse.de (Bruno Park) Newsgroups: comp.dsp Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Jan05.040944.2669@hanse.de> Date: Fri, 05 Jan 1996 04:09:44 GMT References: <1996Jan03.092044.5279@kiae.su> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: WinVN 0.99.5 Lines: 11 In article <1996Jan03.092044.5279@kiae.su>, jkuznetsov@kiae.su (Julien Kuznetsov) writes: > 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. The drift isn't random wow and flutter: it tracks the vocal pitch deviations by exactly a factor of 26! If you are posting from AOL, please read RFC 1036 before posting again. -- Bruno Park -- Hanse-Netzwerk Hamburg "Measuring a record you own is listening, not piracy." From areyes@cern.ch Sat Jan 06 12:45:44 1996 Path: ashpoly!cascade!transat!eunet-fr!teletel!cern!areyes From: areyes@cern.ch (Anton Reyes) Newsgroups: comp.dsp Subject: Re: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Jan06.124544.4309@cern.ch> Date: Sat, 06 Jan 1996 12:45:44 GMT References: <1996Jan03.092044.5279@kiae.su> Organization: European Laboratory for Particle Physics, Geneva NNTP-Posting-Host: cern.ch X-Newsreader: Netscape 1.1N Lines: 10 In article <1996Jan03.092044.5279@kiae.su>, jkuznetsov@kiae.su (Julien Kuznetsov) writes: > 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. Have you checked your sound card's ADC clock? Cheap Sound Blaster cards use uncalibrated ceramic resonators that drift with temperature. -- Anton Reyes Practical Peripherals 14.4 @ ISDN 64k bps "Measuring a record you own is listening, not piracy."