pfarrell;345681 Wrote: > > A 44.1kHz sample will properly capture all possible > 20kHz signals. > See Nyquist and Shannon
Thanks for the tip! Went straight of to Wikipedia to look that one up. Clever chaps these mathematicians. The N&S theorem states: If a function x(t) contains no frequencies higher than B cps, it is completely determined by giving its ordinates at a series of points spaced 1/(2B) seconds apart. So (in theory) a signal that contains frequencies no higher than 20kHz needs data sampling at 1/(2x20,000)or 1/40,000 or 40kHz, as you say. Reading the article on Nyquist and Shannon was interesting. Most of the mathematical notation passes straight over my head, however it is clear that your statement above is not -quite- reality. Near the top of the article it states: "The assumptions necessary to prove the theorem form a mathematical model that is only an idealization of any real-world situation. The conclusion, that perfect reconstruction is possible, is mathematically correct for the model, but only an approximation for actual signals and actual sampling techniques." -My- practical difficulty is that recording at 24/88.2 is producing WAV and FLAC files about 4 times the size of those at 16/44.1 giving me disk space and data transmission issues. Also my first attempt ended up with some heavy distortion on about a quarter of the tracks, so something in the recording chain is failing to cope with the sampling frequency. It was a spitty hissing sound overlaying the music. I was monitoring the whole recording and there was no problem with the analogue signal coming out of the amp. Repeating the experiment at 24/44.1 did not create any problems, so I will probably stick to the lower sampling rate. My high frequency hearing is going anyway so improving the accuracy of the signal at 20kHz is probably a waste of time! -- TheLastMan Matt SB Duet, Synology Diskstation 107+ with FW 2.0-0600 SqueezeCenter 7.2 and SSODS 3 beta 15. Naim 42/110 amp, B&W CM2 speakers. LPs ripped using Linn LP12, Naim 72/Hi-cap, M-Audio 2496. ------------------------------------------------------------------------ TheLastMan's Profile: http://forums.slimdevices.com/member.php?userid=16021 View this thread: http://forums.slimdevices.com/showthread.php?t=53264 _______________________________________________ ripping mailing list [email protected] http://lists.slimdevices.com/lists/listinfo/ripping
