From alindqvist@clari.net Sat Aug 20 11:12:24 1994 Path: ashpoly!cascade!transat!eunet-de!hansebox!clari!alindqvist From: alindqvist@clari.net (Aiko Lindqvist) Newsgroups: comp.dsp Subject: WTB/WTT: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Aug20.111224.6452@clari.net> Date: Sat, 20 Aug 1994 11:12:24 GMT Organization: ClariNet Communications Corp NNTP-Posting-Host: clari.net X-Newsreader: Netscape 1.1N 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. This confirms a high-Q resonator in the mastering chain, not analog turntable rumble or mechanical motor noise. I've uploaded the C source for my decimation and bandpass filter to ftp.ashford-poly.edu. -- Aiko Lindqvist *PLONK* filter active for trolls. Pentium 90 (OS/2 Warp) - NetBSD 1.0 From hfournier@unam.mx Sun Aug 21 04:26:24 1994 Path: ashpoly!cascade!transat!eunet-de!hansebox!unam!hfournier From: hfournier@unam.mx (Hugo Fournier) Newsgroups: comp.dsp Subject: Re: WTB/WTT: 14.2 Hz sub-carrier PSD estimation - Welch vs Burg periodogram Message-ID: <1994Aug21.042624.2447@unam.mx> Date: Sun, 21 Aug 1994 04:26:24 GMT References: <1994Aug20.111224.6452@clari.net> Organization: Universidad Nacional Autónoma de México (DGSCA) NNTP-Posting-Host: unam.mx X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1994Aug20.111224.6452@clari.net>, alindqvist@clari.net (Aiko Lindqvist) 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. Have you checked your sound card's ADC clock? Cheap Sound Blaster cards use uncalibrated ceramic resonators that drift with temperature. -- Hugo Fournier "The carrier frequency does not drift by accident." Amiga 3000T / System 7.5.1