Sound waves(The behavior of soundboards)

[Richard Brekne]

Charles Neuman wrote:

> > From: Robin Hufford <hufford1@airmail.net>
> >      These two rudimentary books give a brief, only lightly mathematical
> > treatment to wave mechanics.  It is incumbent to all that profess to be
> > experts on the subject to comprehend what these, elementary approaches
> > themselves imply, notwithstanding casual observation and that is that a
> > standing wave NECESSARILY IMPLIES RIGID TERMINATIONS AND THE ASSOCIATED
> > REFLECTIONS ARISING THEREFROM.  Otherwise, the standing wave itself
> > cannot exist.
>
> The problem with introductory physics texts is that they treat the world
> in a black and white sort of way: Either a string has fixed terminations
> and therefore supports standing waves or it does not. In the real world,
> you can get standing waves if the terminations are not entirely rigid. The
> terminations need to be... well, rigid enough to support standing waves.
> So, just because standing waves exist, one cannot conclude that the
> terminations must be completely rigid.
>
> Charles

Being one who doesnt believe in absolute conditions to begin with, I would
tend to agree with this point, as far as it goes.

But then after having read Dels last response about agraffes and plateflange
movement in this regard I was struck by the similarity between his words and
the first time I heard the story of the Circle of Sound. Now I know Del is not
an advocate of that idea, yet if all these things indeed do vibrate in some
sense or another, then there must be some ......er... shall I say "path" for
the vibes to follow as it were. So here I am agin...grin... just a wonder'n.

On the other hand again, I have received back a few thoughts from a few folks
having Doctors degrees in physics / acoustics around the world that would seem
to point in a direction that favours the diaphram theory. Tho I have not
pushed for much clarification being greatfull to even hear back from any of
these.

Great fun, and educational as well. I am sure I will end up in all this pretty
well schooled in wave theory, at least as far as that can be taken without
speaking math.

--
Richard Brekne
RPT, N.P.T.F.
Bergen, Norway
mailto:rbrekne@broadpark.no
http://home.broadpark.no/~rbrekne/ricmain.html