Klarinet Archive - Posting 000137.txt from 2000/10

From: "Clark W Fobes" <reedman@-----.com>
Subj: [kl] Barrels & Bores
Date: Tue, 3 Oct 2000 12:37:01 -0400

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I have been making/experimenting with barrels for about 15 years. My =
first barrels were Eb barrels. I was working in a shop in downtown SF at =
the time and just wanted to fool around with the lathe. The only =
material we had at the time that was suitable for making barrels was a =
pair of old claves (you know, the rosewood percussion instruments). My =
first few attempts split and then I had the crazy idea to make a brass =
insert. Later I realized it would be easier just to buy Buffet barrels =
and make the brass insert. There are a few people that have those =
barrels and they really like them. Later I had them machined for me out =
of Delrin, but still used the brass insert. The sound was remarkably =
different than solid wood barrels. I believe the added density of the =
brass caused the barrel to absorb less vibrations and created a more =
brilliant sound.

There are many factors that affect the sound of the barrel, but the bore =
configuration has the greatest influence. A conical bore with an average =
(nominal) bore of say .585" will sound different than a pure cylinder =
with the same nominal bore. Intonation is affected not only by the =
length of the barrel, but the internal dimension. A smaller bore =
effectively reduces the volume of the mouthpiece/barrel cavity and =
generally raises the pitch. But a smaller bore in the barrel will also =
reduce the size of the twelfths.

I have not done any experimenting with the "cross section" shape of =
barrels. In the '70s Rovner manufacured a synthetic barrel that had a =
rectangular bore - not even a square.The sound was very free, but not as =
much of a difference in sound as one would expect from such a radical =
departure. An oval shape would be difficult to make, but with C&C lathes =
it is probably not at all impossible. Rotating a barrel on the clarinet =
can produce different qualities of resistance. This is due to the bore =
of the barrel and perhaps the bore of the clarinet not being concentric. =
As one rotates the barell the "step" at the end of the mouthpiece is =
more or less open. This step or "choke" (or lack of) at the point where =
the mouthpiece and barrel meet is critical. In the US we play fairly =
large bore mouthpieces (exit bore ca. .589" -.595). Generally a =
reduction (at the top of the barrel bore) to at least .589 is preferred =
and creates better modal ratios.

With repsect to Dr Gibson's observations about the weight of the barrel =
I have some disagreement. I believe that the density of the material has =
more of an influence - up to a certain point. In my experimenting with =
outside shape I found that less wood can make the barrel feel more =
lively, but it does not seem to translate into a more brilliant sound. =
At some point (and I did not weigh the barrel) when I took too much wood =
off the barrel, it became sluggish and dull sounding. However, the =
density of the material seems to have some influence on vibration =
absorption or reflection. There probably is some type of inverse =
correlation of density and weight. The wall material ( which affects =
wall smoothness) has an audible effect on the clarity of the sound.

One final point is that I have noticed that the rings (also known as =
ferrels) affect the way a barrel vibrates and feels to the performer.

I must reiterate that bore configuration has the greatest influence on =
barrel performance and sound. All of the other sublte influences from =
materials and outside shape influence our physical and aural feedback =
(Which are very important!), but probably are not noticeable from a =
distance of ten feet.

Clark W Fobes

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