From: lstowell@pyrnova.pyramid.com (Lon Stowell)
Newsgroups: rec.audio
Subject: More Psuedoscience...: A Golden-Ear perspective on CD players.
Keywords: flame bait, CD accuracy
Date: 8 Apr 92 01:00:17 GMT
Reply-To: lstowell@pyrnova.pyramid.com (Lon Stowell)
Organization: Pyramid Technology Corp., Mountain View, CA

In article <1992Apr7.222913.16264@cunixf.cc.columbia.edu> reha@cunixf.cc.columbia.edu (Reha Elci) writes:
>The CD sampling rate is at 44Khz. Why hasn't anybody pointed out that this 
>sampling rate is not really sufficient to reproduce accurate high frequency
>signals? If the sampling rate was, say, 1Mhz or something, I would have
>believed fairly accurate reproduction of signals but just 2x the sampling
>rate of the frequency you are trying to quantify does not seem sufficient.
>Can interpolation and extrapolation, no matter how clever, really reproduce
>the correct shape of a 20 microsecond period signal?
>
    Are you saying that it is counterintuitive, or is it that you
    just fail to understand the theory?

    For a hint,...at 20 Khz, what is the difference in the spectrum
    between a square wave, a sine wave, a triangle wave?


>The number of bits is also somewhat of a problem. 16 bits mean, at best,
>1 part in 65536 parts resolution. -20 * Log (1/65536) = 96.33 dB of
>dynamic range (is this how it is calculated??). This also seems somewhat
>low if you are interested in accurate and detailed sound quantification.
>
     The number of bits does NOT have any set relationship to the
     dynamic range...you may want to check the FAQ's or some of
     Max's postings.

     You need to know what each bit represents before you can make
     any assumption whatever about the number of bits and the
     dynamic range.  Suppose you decided that each bit represents
     a linear voltage relationship, a 0.1 dB change in power, a 1 dB
     change in power [ratio], a 3 dB change in power ratio...etc.


     And you may also want to head for an acoustics library and look
     up the ambient noise levels (in dBA) of a home, a suburban
     home, a city street, an apartment, an automobile, a theater, a
     concert hall, etc.   

     Then go measure a symphony orchestra or a close miked piano and
     note the actual SPL's output.  

     And of course you may want to look up the dynamic range of the
     competing media.  

>Given the specs above, it is not too shocking to hear how some people
>may prefer analog recordings, especially good ones, to CD reproductions.
>
     Given that your specs aren't....they are merely mental
     manipulation.   And that you have committed the grevious sin of
     NOT comparing the state of the art in the analog media....

     Nor have you bothered to examine the TYPE of distortions and
     their psychoacoustic effects.....


>I am a strong supporter of digital technology and it is the best delivery
>system of *any* type of information, be it sound or video. However, the
>design engineers never really give enough credit to the consumers; thats
>why the CD technology is "under-designed".
>
     And of course you neglected to consider the difficulties of
     designing an analog circuit with even the dynamic range that
     you claimed for CD.  Or a power amplifier or speaker with that
     dynamic range?


      Sorry Reha, I have no problem with you preferring analog over
      digital. This is a matter of personal preference.... 

      But then when you go on with mere speculation and try to pass
      it off as factual REASONS for you preference, you are guilty
      of the typical non-techie phile intellectual dishonesty often
      found in salesslime.

      The odds of you ever successfully IMPROVING the digital
      process are pretty slim unless you are willing to spend some
      real study time rather then a bit of mental
      masturbation....then presenting your (incorrect by the way)
      theories as supporting fact.  Digital may be counterintuitive
      to some, but it ISN"T rocket science...and it isn't what your
      misguided theories says it is either.