Re: Audi Audio

[ti@amb.org (Ti Kan)]

Nate Stuart writes:
> I am in the process of installing a PC into the trunk of my '87 5kcstq. Why
> you ask?!?
> ...

Check out this site for a Linux-powered MP3 player for the car:

	http://www.empeg.com

One thing to note, though.  MP3 is a lossy compression algorithm.
While it is a psychoacoustically-tailored algorithm, nonetheless it
produces audible side effects when decoded and played back, particularly
if the file was encoded with aggressive compression.

I have my PC connected to my home stereo system with high quality
amplifiers and speakers, and did some careful listening tests of a very
well recorded CD, and MP3 files encoded from the digital audio data directly
read from the same CD.   I tried MP3 compression rates of 64Kb/s, 128Kb/s,
192Kb/s and 256Kb/s (the higher the number, the less aggressive the
compression).  As expected, the lower Kb/s files sounded bad, the higher
the Kb/s the better.  There is an artificial, metallic quality to the
sound.  The spatial details were also dramatically lost in the encoding
process.  256Kb is barely tolerable, but at the less aggressive
compression rates the audio files are getting pretty big, like over
10MB per 5-minute song.

My long winded point is, that MP3 is cool, but is no way a substitute
for a good CD player, if quality of sound is of importance to you.
There are hypes about MP3 being "CD quality", well by definition it can't
be.

I also have some reservations about using computer-grade hard disk
drives in an automobile.  You gotta have to shock mount it very well,
and I wonder about the temperature and humidity extremes it might
encounter...  Much better to use a flash RAM based solid state disk ($$$).

Sorry for the non-Audi content.

P.S. I have collected quite a bit of MP3 music on my computer which
I use for non-critical background music.  I have a Jaz 2GB SCSI drive
which is ideal for this sort of thing.  At 2GB per disk cartridge I can
store over 20 CDs worth of music each.  All UNIX-powered... no M$ software
here.

-Ti
96 A4 2.8 quattro
84 5000S 2.1 turbo
80 4000 2.0
-- 
    ///  Ti Kan                Vorsprung durch Technik
   ///   AMB Research Laboratories, Sunnyvale, CA. USA
  ///    ti@amb.org
 //////  http://metalab.unc.edu/tkan/
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