andy_simpson wrote on Thu, 15 September 2005 16:46 |
I think that you're missing the point.
It's not bandwidth that digital lacks over tape. It's the spatial quantization that digital enforces, which can easily be measured in spatial terms (ie. 1.7cm).
To explain further; when you have a stereo signal, the time differences between left/right are limited to steps of 1.7cm by the sampling rate.
I am trying to illustrate that the sound made by acoustic instruments is as complex as their phyiscal shape and that 1.7cm quantization of this is very poor indeed. This applies to reverb and all other aspects of acoustic sound.
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You are trying to illustrate a hypothesis, and your hypothesis is flawed.
The wavelength of a 20 kHz signal is 1.7 cm, no doubt. It doesn't make any difference if it is captured "analog" or "digital". In air, the spatial separation of two pressure peaks of that 20 kHz signal will be (approximately) 1.7 cm. Space a pair of microphones 1.7 cm apart, and at some instant in time, both will sense an amplitude peak (in the absence of reflections), and then one micro-second later, they will both sense an amplitude ever so slightly less than that peak value. Approximately 12 micro-seconds later, they will both sense zero. And so on, and so on, and so on. There is no lack of "spatial information".
Look, Nyquist works. There may have been various implementations of digital audio that were less than spectacular, but the reasons weren't because Nyquist doesn't work. You can't really get around the fact that, properly implemented, digital audio is more
accurate (not necessarily "better") than analog, at sampling frequencies far below 192 kHz. Maybe 44.1 kHz is cutting it a bit close, but this "spatial resolution" red herring is just that . . . a red herring.