Klarinet Archive - Posting 000168.txt from 2007/09

From: Robert Howe <arehow@-----.net>
Subj: [kl] Blow out some more!
Date: Sun, 23 Sep 2007 17:59:09 -0400

Some further (and may I hope final?) reflections on blown out clarinets and
oboes.

If blow out is a tone hole crud phenomenon, it will occur equally in plasti=
c
oboes and clarinets as in wooden specimens. I have never heard of such a
thing as a blown out plastic oboe. Has anyone else?

Dan Leeson asks for proof of blown out clarinets, no doubt looking for a
lack of scientific data so that he can dismiss a colleague=B9s observation as
mere legend. But the writer who compared this to PMS=8Bwhich I treat every
day=8Bwas on the money; another example of a once derided sickness would be
Lyme disease. Absence of proof is NOT proof of absence. What proof do you
need, oh DNL, beyond one or two colleagues describing the phenomenon? What
experiment would you propose to test the theory that a clarinet can blow
out? What experiment could be more valid than to throw a thousand or two
thousand clarinets out into the world, have people play them, and then have
those folks report their experiences=8Bjust as Fred J has done? Has any Blow
Out Denier played Fred's clarinet?

On reflection I can propose an explanation for the occurrence of blow out i=
n
oboes but not often in clarinets and bassoons. Replacing the top joint of =
a
blown out oboe fixes the issue; thus it seems to be a top joint phenomenon.
Oboes have a very pronounced conical bore, with a conicity of 2.5% or so.
A bassoon=B9s conicity is about half that and a clarinet=B9s is essentially 0 i=
n
the upper joints. Thus in the top joint of an oboe the bore will constantl=
y
be exposing new vascular bundles in the grain; the interior of an oboe is
much more akin to end grain than to side grain. In a clarinet, essentially
no new bundles will be exposed as one moves along the bore. In a bassoon,
the very slow taper and wide bore will cause the exposure of fewer bundles
per unit length than in an oboe; maple being less dense than grenadilla,
even fewer bundles will be present to become exposed.

Let us now consider that the opening of the bindle into the bore allows the
passage out of oils and the passage in of saliva, thus permitting the
exposure of deeper wood to the acidity of the player=B9s saliva. I have seen
(in a rosewood oboe by Loree) tiny little deformations of the bore where
each bundle opens. If any of these processes occur in an playing
time-dependent fashion, then an oboe will assuredly be altered much more
quickly than a clarinet or bassoon. When looking at a large population of
instruments, even if this is a slow process it would be manifest as oboist=
s
noting the phenomenon and clarinetists not.

Good afternoon all,

Robert Howe

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