🚀 go-pugleaf

In article <2070@sauron.Columbia.NCR.COM> wte@sauron.UUCP (Bill Eason) writes:
>In article <1990Mar20.162041.4639@ux1.cso.uiuc.edu> forbes@aries.scs.uiuc.edu (Jeff Forbes) writes:
>>
>>Aren't all of the digitally mastered recordings sampled at ca. 45kHz?
>>Which would make the arguemnt about CD response moot.
>>
>>		Jeff
>
>Enter here the Nyquist criterion which says that the sampling frequency
>(44.1 kHz really) must be >= two times the highest analog frequency being
>recorded.  Therefore, the highest frequency which can be accurately 
>reproduced from a 44.1 kHz digital recording is 22.05 kHz, which is within 
>the range of hearing of several folks posting here.  I suspect my audible
>range reaches up there, too, since I can hear department store burglar
>alarms and CRT flyback transformers.
>
>-- 
>Bill Eason   (803) 791-6348	...bill.eason@ncrcae.Columbia.NCR.COM
>NCR Corporation
>E&M Columbia     3325 Platt Springs Road     West Columbia, SC 29169


I am thoroughly familiar with the Nyquist theorem. The point I was trying to
make was that a large fraction of the music today is digitally mastered at
44.1kHz which would limit all media to 22.05 kHz maximum frequency. A record
made from a digital master can have no better frequency response than that of
the master. Any higher frequency heard are noise. I can hear TV flyback 
transformers as well, but that is only 15.75 kHz. I certainly can't here it in
my multisync when it is at 35kHz. I have been experimenting with piezoelectric
transducers, and I can hear 17.5kHz in a noisy lab. With a quiet enviroment 
and more sound power I could probably hear above 18kHz. I do wonder what the
actual percentage of the ADULT population can hear sine waves above 20kHz.

		Jeff