Klarinet Archive - Posting 000335.txt from 2004/06

From: ormondtoby@-----.net (Ormondtoby Montoya)
Subj: Re: [kl] Concentricity of barrel bore to upper joint bore; was:
Date: Mon, 21 Jun 2004 14:51:27 -0400

Walter Grabner wrote:

> I believe that you are asking if the bore of a
> barrel must be concentric with the bore of the
> upper joint of the clarinet. [snip] In actual
> practice, this [being concentric] seems to
> make little difference.

Thank you for the reply, Walter. It happens that I wasn't measuring
concentricity, **but** it is interesting to hear one more reinforcement
of the idea that *area* (of each cross-section) is the controlling
factor, not shape

It happens that I was measuring the bore's diameter, and then rotating
the barrel 90 degrees around its longitudinal axis, and then measuring
it again (at the same end). The two measurements did not agree, thus
showing that my barrel's bore (which came from the factory, and I'm
*not* intending to mess with it!) no longer has a circular
cross-section. This is what I meant by "out of round".

I also noticed that the barrel's bore at the end next to the joint truly
*is* smaller (by ~0.15 mm in my case) than the bore of the joint's
tenon, thus confirming that there is a "choke" at the lower end of my
barrel.

Out of curiosity, I took advantage of a careless mistake to finish off a
barrel with a severe "choke" (I don't want to admit *how* severe!).
While the barrel missed by 10-20 cents in the upper registers (i.e.:
were not "on the needle"), and even some adjacent semitones did not
track with each other, the barrel was not as dramatically awful as I had
expected. and it was 'right on' for all of the scale below B-natural ---
assuming I wasn't unconsciously bending notes --- including throat
B-flat, which I was not expecting to be 'on'. So it was interesting to
witness how 'awfully' some parts of the scale can play while other parts
sound really good. As you've already said, measuring the 12ths is
essential.

I don't have any concept (yet) of where the pressure peaks and valleys
for various notes occur in a barrel, and so (eventually) I'm going to
try doing some reading and see if I can understand what the books say
about this.

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