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From: hachong@watmath.UUCP (Herb Chong)
Newsgroups: net.audio
Subject: Re: Re: Tighter bass and edgeless piano
Message-ID: <16538@watmath.UUCP>
Date: Thu, 19-Sep-85 12:07:38 EDT
Article-I.D.: watmath.16538
Posted: Thu Sep 19 12:07:38 1985
Date-Received: Fri, 20-Sep-85 04:16:02 EDT
References: <1636@druxu.UUCP>
Reply-To: hachong@watmath.UUCP (Herb Chong)
Organization: U of Waterloo, Ontario
Lines: 87
Summary: 

In article <1636@druxu.UUCP> tlz@druxu.UUCP (ZrustTL) writes:
>Heh, heh!  Ear training? Flat frequency response with mid-fi or
>lo-fi results?  What has happened here?
>
>Let me try the question again with clarification .  What is
>meant by tigntening bass and taking edges off of piano as it relates
>to things that happen to the specifications of audio equipment?
>Since something must happen (changes can be heard by the "finest
>and most sensitive instruments -- OUR EARS") then this obviously
>MUST be measurable by any reasonable test equipment (which clearly is
>less subjective and EVEN MORE SENSITIVE then our ears.  

tightening the bass can refer to how well damped the low frequency
driver is.  this is seldom specified by manufacturers and interactions
with the power amplifier can change it.  it can also refer to frequency
response in the lower 3 or 4 octaves audible to the human ear.  i'm
sure that there are other definitions too.

edginess can refer to a couple of things:  a peak in the response such
that several of the upper harmonics of a note are excessively
emphasized; distortion of the signal reproduced, particularly
intermodulation distortion, and unwanted resonances in the mid and high
frequency drivers of speakers.  again, i'm sure there are other
circumstances that are loosely described by this term.

>Is there another domain of sound reproduction that has escaped 
>detection by electronic instruments but is be obvious to the ear?  
>Don't give me this "you can hear it but I don't know why" stuff.
>I hear that from stereo store sales people and its garbage.
>Everything happens for a reason and anything that can be heard
>can be measured.

probably an infinite number.  all these specifications printed are
known to correlate with listening quality, but there is nothing that
says that we've measured all there is to measure.

>Everything happens for a reason and anything that can be heard
>can be measured.

but there is more than just measurement going on here; there is
interpretation.  a parallel can be drawn with the current research in
computer vision.  a camera can record and measure far more than the
human eye can, but all existing computer vision systems fall far short
of the human visual system because there is an immense amount of both
information processing and knowledge being utilized to interpret an
image.  

the human hearing system is also doing the same type of processing and
is also using a huge knowledge base.  we cannot help but interpret
everything we see and everything we hear.  our senses are not objective
in the sense that instruments are.  we bring too much of our own
experiences into the listening.  it maps sounds back to something that
we have experienced before.  that is the reason why the human hearing
system is poor at differentiation between signals that are extremely
similar.  it tries to adapt to something recognizable and previously
experienced.  

suppose that you have never heard a musical instrument before and have
never had anyone describe it to you either, for instance, a flute.  how
would you determine if the reproduction of it is correct purely by
listening to the recording.  yet someone who has heard it being played
live may be able to tell you that the person is blowing it from the
wrong end.  that is the crux, that the person has heard it before.

ever notice how different music is when you're at a concert when compared
to a recording of the same concert being made under the same conditions
(i.e. same microphone location as yourself and audience).  the differences
are not in the sound so much as the experience, and that cannot yet be
reproduced.

>I'm all for using ears to judge quality.  That's not the issue here.

ears can only detect gross differences.  quality is a based upon
experience as much as specifications.  the threshhold is different for
different people depending on training, musical exposure, experiences,
and physical differences.  for the most subtle differences, only
double-blind testing under rigidly controlled conditions can reliably
differentiate between them.

Herb Chong...

I'm user-friendly -- I don't byte, I nybble....

(will disappear Spetember 30)
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