<div class="gmail_quote">On Wed, Apr 21, 2010 at 1:51 AM, Arnold Krille <span dir="ltr"><<a href="mailto:arnold@arnoldarts.de">arnold@arnoldarts.de</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
The highest frequency possible to reproduce -with correct amplitude- is half<br>
the sampling-rate _only_ if the phase is aligned to the sampling-clock so that<br>
minima/maxima of the sinus are correctly sampled. If its out of phase, the<br>
amplitude is not reproduced correctly.<br></blockquote><div><br>Wouldn't that only apply to a signal *at* Nyquist, which by definition
is not covered by the sampling theorem? How would it even be possible for a signal at, say,
22.04 kHz be phase-aligned to the sampling clock?<br> </div><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
It is easy to understand that this correlation between phase and correct<br>
amplitude also affects frequencies below half the sampling-rate. Might be as<br>
low as quarter of the sampling-rate, which in case of the CD is 11kHz. Below<br>
that you will have more then four samples to reproduce the sinus wave.<br>
That is in fact another reason to do the recording, mixing and mastering in<br>
more then 44kHz...<br></blockquote><div> </div></div>This is a pretty bold claim, and contradicts Nyquist and other literature. Do you have a citation for the claim that frequencies "as low as a quarter of the sampling-rate" are damaged by sampling?<br>
<br>