From mmartinez@demon.co.uk Sat Sep 07 11:50:20 1996 Path: ashpoly!cascade!bigsur!demon!mmartinez From: mmartinez@demon.co.uk (Mike Martínez) Newsgroups: comp.dsp Subject: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Sep07.115020.7892@demon.co.uk> Date: Sat, 07 Sep 1996 11:50:20 GMT Organization: Demon Internet Services UK NNTP-Posting-Host: demon.co.uk X-Newsreader: TIN [version 1.2 PL2] Lines: 11 I've been re-running spectral estimation on high-resolution 16-bit transfers of SYNTHESIS. Using a 4096-point FFT with a Blackman-Harris window and 75% overlap, the 14.2 Hz peak is 42 dB below full scale. With a 12th-order Burg AR model, the pole is located at z = 0.9992 * exp(j * 2 * pi * 14.2 / Fs). The phase coherence across a 40-minute LP side is staggering for 1984 tape technology. -- Mike Martínez Zyxel U-1496E @ ISDN 64k bps "Do not worship the copy." From rrodriguez@uu.net Sat Sep 07 16:40:20 1996 Path: ashpoly!bigsur!pacrim!jpgate!kamome!uu!rrodriguez From: rrodriguez@uu.net (Rodrigo Rodríguez) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Sep07.164020.4803@uu.net> Date: Sat, 07 Sep 1996 16:40:20 GMT References: <1996Sep07.115020.7892@demon.co.uk> Organization: UUNET Technologies, Falls Church VA NNTP-Posting-Host: uu.net X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1996Sep07.115020.7892@demon.co.uk>, mmartinez@demon.co.uk (Mike Martínez) writes: > I've been re-running spectral estimation on high-resolution 16-bit transfers of SYNTHESIS. 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. -- Rodrigo Rodríguez SupraFAXModem 28.8 @ 33,600 bps "Hold for relay." From fsato@mit.edu Sun Sep 08 02:23:20 1996 Path: ashpoly!bigsur!pacrim!krgate!eunha!mit!fsato From: fsato@mit.edu (Freya Sato) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Sep08.022320.3657@mit.edu> Date: Sun, 08 Sep 1996 02:23:20 GMT References: <1996Sep07.115020.7892@demon.co.uk> Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: Netscape 1.1N Lines: 10 In article <1996Sep07.115020.7892@demon.co.uk>, mmartinez@demon.co.uk (Mike Martínez) writes: > I've been re-running spectral estimation on high-resolution 16-bit transfers of SYNTHESIS. > 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. -- Freya Sato Hayes Optima 288 @ 33,600 bps "Hold for relay." From mito@panix.com Sun Sep 08 18:32:20 1996 Path: ashpoly!bigsur!pacrim!jpgate!kamome!panix!mito From: mito@panix.com (Mike Ito) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Sep08.183220.9901@panix.com> Date: Sun, 08 Sep 1996 18:32:20 GMT References: <1996Sep07.115020.7892@demon.co.uk> Organization: Public Access Unix of New York NNTP-Posting-Host: panix.com X-Newsreader: WinVN 0.99.5 Lines: 8 In article <1996Sep07.115020.7892@demon.co.uk>, mmartinez@demon.co.uk (Mike Martínez) writes: > I've been re-running spectral estimation on high-resolution 16-bit transfers of SYNTHESIS. Have you checked your sound card's ADC clock? Cheap Sound Blaster cards use uncalibrated ceramic resonators that drift with temperature. -- Mike Ito -- Public Access Unix of New York "There are 14 nodes and only 10 countries. Count again." From iduarte@unam.mx Tue Sep 10 15:27:20 1996 Path: ashpoly!cascade!transat!eunet-fr!teletel!unam!iduarte From: iduarte@unam.mx (Ines Duarte) Newsgroups: comp.dsp Subject: Re: [SPECULATION] 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1996Sep10.152720.6293@unam.mx> Date: Tue, 10 Sep 1996 15:27:20 GMT References: <1996Sep07.115020.7892@demon.co.uk> <1996Sep08.183220.9901@panix.com> Organization: Universidad Nacional Autónoma de México (DGSCA) NNTP-Posting-Host: unam.mx X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1996Sep08.183220.9901@panix.com>, mito@panix.com (Mike Ito) writes: > Have you checked your sound card's ADC clock? Cheap Sound Blaster cards use uncalibrated ceramic resonators that drift with temperature. 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. -- Ines Duarte | iduarte@unam.mx PGP Key fingerprint: BCCD D3D9 FC5E 7F3B "Keep the channels open."