Klarinet Archive - Posting 000600.txt from 1997/02

From: CLARK FOBES <reedman@-----.COM>
Subj: R-13 Intonation
Date: Mon, 17 Feb 1997 14:08:07 -0500

I apologize for not quoting all of the many interesting parts of the
string in this discussion. I will try to incorporate previous thoughts
as I go.

The Buffet R-13 does indeed have some problems with the overall tuning
schema, particularly the R-13 A clarinets. The fact of the matter is
that Buffet and Boosey & Hawkes (the parent company of Buffet) are so
nervous about doing anything to disrupt their highly profitable line of
R-13 clarinets that any improvements are usually reserved for other
models. The most significant change Buffet has made in recent years was
to move the register vent up toward the mouthpiece about 3mm. This
change was first used, I believe, in the RC model clarinets and much
later in the "Festival" clarinet. The RC model clarinets have a
slightly larger upper bore and have two reversed cones in the upper
joint rather than the three of the R-13.Common designs prior to 1950
were either a pure cylinder or a constantly reducing upper joint.

(RC, BTW, stands for Robert Caree and was designed by him shortly
before he died. Robert Caree was also the designer of the R-13 Clarinet
which was introduced in in 1950. Mr Caree's inovative design became
known as "poly-cylindrical".)

However, it is precisely the bore design of the R-13 that gives it the
unique tonal character and resistance that so many of us have come to
enjoy over the years. I find that overall the modal parameters on the
R-13 are very manageable, particularly in the case of a good Prestige
model, which I play.

Because I play an R-13 I have designed my mouthpieces and barrels to
accomodate some of the inherent tuning problems. The original design of
the R-13 Bb calls for a barrel with a nominal bore of 14.95mm with no
linear reduction (taper). This usually translates into about .589"-
.590" on most new Buffets. The reason for this is to compensate for the
flattening in the third mode (tones above high C, known usually as the
"altissimo"). This probably works with the Buffet mouthpieces that have
a small bore (about 53mm in length).

For several reasons most players have come to prefer mouthpieces that
represent the Kaspar paradigm of a large bore (55mm) with a significant
taper. This really compounds the problems of the lowered third mode and
so most of us who like these larger bore mouthpieces need a reduction
in the upper bore vis a vis the barrel. Welcome Hans Moennig and the
reverse cone taper. This was not a unique idea. It had been in place
with German clarinets for many years, but we must credit Mr Moennig for
introducing the use in this country.

Over years of experimenting I have come up with a model that I like
very much and has extremely good modal parameters for the Buffet R-13.
My mouthpiece bore actually has TWO tapers and so is not completely
linear. I have also settled on a bore for my Barrels that is slightly
smaller at the top diameter than Moeenig barrels and does not reduce as
much over the length of the taper.

An excellent discussion of Clarinet bores and design can be found in:

O. Lee Gibson. "Clarinet Acoustics". Indiana University Press, 1994

Clark W Fobes