Sound waves(The behavior of soundboards)

Richard Brekne Richard.Brekne@grieg.uib.no
Mon, 24 Dec 2001 00:47:18 +0100


Ron Nossaman wrote:

> >Oh come on Ron,... Physically displacing one string with your finger in no way
> >simlulates the real life situation of the vibrating system. Of course you can
> >push the bridge and sound board down with your fingers.
>
> No, I pushed down the unison, the bridge moved. I pulled it up too, like
> the hammer does when it hits the strings,

Is that really reflective of how the strings influence the bridge ? If so then you
have some pretty good cards to be sure.

> and the bridge moved the other way.

......


> Wasn't the discussion about whether or not the bridge can be moved by
> the string,

I was under the impression we were trying to get to the root of the mechanisims for
transfer of energy from the vibrating strings to the soundboard.... or stated
another way... how sound is actually produced from the panel.

> or are we now to presume that the string isn't deflected by the
> hammer as well?

Grin... not by me.... even I may be an stupid, but I am not dumb..


> > That does not show, nor
> >does anything else you have had to say so far, that the board gets moved
> by the
> >bridge which is moved up and down and forward and backswards physically by the
> >strings vibrating. No offense meant, but proofing something to be true or
> false
> >requires a little bit more then opinion,  unsupported declarations of some
> >insight into the realm of physics, and oversimplified examples that are
> >questionable in terms of their relevance to the subject matter at hand.
>
> Who has the burden of proof here? I thought there were two theories in
> question, not just one, and I haven't heard what I consider a remotely
> adequate argument or test to support the other theory. As I said before,
> Instrumentation and an intelligently run test is the only way to say. I
> don't have the proper instrumentation to test it in real time. Whether the
> test data would be believed or not is another question.
>

I'll go along with you quite a ways on this point actually. And I apologize for not
seeming more evenhanded in any criticisms I may have written. I do think I wrote a
bit a week or so ago more in that spirit however. You are correct tho. The other
side has not "proven" their theory, nor have they been able to refute yours
adequately.


>
> >Now, none of this means I am taking sides with JD on this... I am not at all
> >convinced he is correct, tho I find his thoughts interesting enough.
>
> You sure sound convinced to me.

Then you have misread me... as you have before.  I have said that I thought their
ideas were interesting and that the argumentation against that I have seen so far
has been weak.  I dont think that qualifies as any conclusion about which theory is
the best.

> > I have seen a lot of scoffing and the
> >like.
>
> Yes, so have I.

To be fair.... point taken and yielded.  Takes two to roll in the mud as they say.

> Ron N

I am far from convinced of either side, and tend to think probably the truth is
more a combination of things really, but that all is a bit over my head. Discussion
technique however, and logic tools employed in that endeavour are another matter.
My reaction is as is usual in these matters... one directed at the lack of relevant
and adequate proofs / documentation for declared standpoints.

OK... NOW !!...grin.. I am truly off for Christmas..... people to visit, places to
go, things to do. Merry Merries one and all.


--
Richard Brekne
RPT, N.P.T.F.
Bergen, Norway
mailto:rbrekne@broadpark.no




This PTG archive page provided courtesy of Moy Piano Service, LLC