soundboardinstal again

[ranjacob@umich.edu]

Cy Shuster, Ron Nossaman, and others,

Thanks for this reference, and for your point about learning from
theory and by well-presented analogies.  It happens that for various 
reasons I haven't recently been able to get into journal
literature that hasn't been anthologized, and haven't yet got hold of Del 
Fandrich's articles.  But Ron does have a point in a case
like mine. If I read theory that is new to me and quite fascinating, such 
as that of pulses travelling within the speaking
length and being (partially) reflected from different kinds of
termination, it still is true that I lack the mastery of trigonometry, 
calculus, and whatever else that would help me to
understand, in a range of cases and reported or observed values,
what results of calculation might reasonably be expected to be
significant in design, and what results might reasonably not.
And, at the moment, I'm not set up to make my own listening experiments. 
So, for example, if I were to have to make choices reasonably soon, a good 
deal of them would be based on "faith" or
"authority" or "trust".  (Nothing new or always bad about that,
of course.)

A very small case in point:  from what I've seen of a recent
sales brochure from Bl"uthner, the company appears to be saying
that they use rib crowning, and make their soundboard assemblies
starting from 5% to 6% moisture content.  They refer to their
approach to crowning as not aiming so much at spherical crown as at crown 
along the line of the long bridge (which might be another way of saying 
that they use rib crowning). They also point out that
they bevel the rims to fit the assembly's perimeter bearing surface.  In 
this case, since (if I recall correctly) Ron has
questioned the value of rim beveling, at least under certain conditions, I 
wonder whether the maker is simply following its
own (or even others') traditions, or has done its own research
to try to determine whether or not it makes a difference. (There
is, however, plenty about the experience of playing this maker's
new instruments that engenders a great deal of "faith" or "trust".)

I've known from reading the list that length of backscale is
considered important.  The response has made me think more about
why there are rebuilders who (if I recall correctly) find it worthwhile to 
to replace standard hitch pins with vertical hitch pins.

Thanks,

Randy Jacob
University of Michigan Library

--On Wednesday, July 30, 2003 4:27 PM -0500 Cy Shuster 
<charter1400@charter.net> wrote:

> Ron,
>
> Different people learn best via different mechanisms.  You have the luxury
> of having learned through lots of hands-on experience.  For those of us
> who have never touched a SB outside of a piano, theory is helpful, along
> with analogies; that's what I found interesting.  In particular, I
> thought the article contributed a lot of acoustic theory, born out by
> measurement, that directly applies to the sound transmission mechanisms
> through the bridge that the list was trying to wrestle to the ground last
> year (such as how can there be motion in a node).  And I thought it was
> interesting (but maybe not useful) that inharmonicity is caused by higher
> frequencies propagating faster through the string (and to see the
> oscilloscope trace).
>
> --Cy Shuster--
> Rochester, MN