Klarinet Archive - Posting 000601.txt from 2000/01

From: "Clark W Fobes" <reedman@-----.com>
Subj: [kl] Mouthpieces and Intonation
Date: Mon, 17 Jan 2000 21:46:40 -0500

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It has been interesting to see Walter's enthusiasm for mouthpiece =
design. These are all questions that all of us who try ro make superior =
mouthpieces must ask and understand. Bravo, Walter.

I may have misunderstood a point Walter was trying to make when he =
stated:

"If you have a mouthpiece with a bore that flares to 15.1 mm, and you =
put it=20
> on a Buffett R-13 with a 14.76 bore, what will happen????"

Am I to understand, Walter, that you believe that the bore at the end of =
the mouthpiece (exit bore) should match the bore at the top of the =
barrel?

If one takes 14.76mm to be the "nominal" bore of a standard R-13 , this =
number refers only to the area of the bore in approximately the middle =
third of the instrument. The polycylidrical R-13 bore has two more steps =
in the top third of the clarinet that results in a bore at the top joint =
of about .587" give or take a few thousandths. (Not very consistent!)

Before I go much further I would like to start speaking to bore =
dimensions in terms of .001" of an inch. This is a much more accurate =
way of measuting and is more meaningful to me at least. Multiply =
Walter's metric equivalants by 39 and we can reach a very close =
approximation to .001"

15.1 x 39 @-----.589" (rounded up)
14.76 x 39 @-----.576" (rounded up)

If you were to try to play a barrel with a top dimension of .576 on a =
Buffet R-13 you would be very unhappy. Most Moenning barrels are about =
.588 -.589 at the top and then taper to about .578-.579. Standard Buffet =
barrels start at about .588, but have
very little taper

.589" is a little small for the exit bore of a mouthpiece unless you are =
using an old Chedeville style bore that has less taper and is a bit =
larger at the top bore than most of the Kaspar moutpieces .

In my work I have found that the barrel/mouthpiece combinations is =
extremely important. One can correct some inherent deficiencies in a =
mouthpiece with a properly adjusted barrel. Most American players now =
favor a medium large bore
(like the Kaspar mouthpieces) and an inverted cone barrel.

Most *good* Kaspars that I have measured have exit bores right around =
.595". If one were to use a barrel with a similar measurement at the top =
the tone would be quite diffuse and (assuming a barrel length of 65mm =
-66mm) would be quite flat in the throat tones. A properly made inverted =
cone barrel balances the overall volume of the mouthpiece/barrel bore =
and will bring the larger bore mouthpiece into good modal ratios.

Walter is also correct about the problems of bore "warpage" during the =
cooling process. This is why it is absolutely essential to use reamers =
to bring the bore up to specs. I use 4 reamers when working on or =
checking the bores of my mouthpieces and they all have slightly =
different functions.

Another interesting aspect of adding a sudden reduction to the bore just =
below the mouthpiece

>=20

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