 The Clarinet BBoard
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Author: Marcia Nottle
Date: 2001-12-06 20:43
I have come across this word many times (twice in the last 5 minutes) on this BB in reference to clarinet bores but still do not know what it means. I have done a search but am none the wiser. Can someone please put me out of my misery and provide a definition?!
Marcia
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Author: Douglas
Date: 2001-12-06 21:55
Considering the many postings from Ken Shaw that give answers of unusual depth, we could probably call Ken a "poly-helpful" contributor.
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Author: Fred
Date: 2001-12-07 01:54
Don Q, are you inferring that the bore of any clarinet is by definition polycylindrical? How do you describe the difference between the Selmer Series 9 and the Selmer Series 9*? Or between the pre-1955 Buffet Professional models and the post-1955 R-13's?
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Author: sarah
Date: 2001-12-07 02:03
Don, I think you should take your own advice. Ken's post makes perfect sence and it seems to me that polycylindrical IS the right word.
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Author: William Hughes
Date: 2001-12-07 03:51
1 - It probably makes no difference what term is used.
2- I am not currently a geometry student, but my son is. Poly = many. Cylindrical refers to cylinders. Conical refers to cones. As I read the Ken Shaw post (which is very enlightening and well written) the three cylindrical bores are blended into one another, producing, in effect, a taper from one sized cylinder to another, which would be a cone. Hence, Don's humble suggestion that "poly-conical" would be an appropriate term is not at all far fetched to me.
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Author: Matt Locker
Date: 2001-12-07 13:41
William & Don Quixote:
From Miriam-Webster:
cone:"a solid bounded by a circular or other closed plane base and the surface formed by line segments joining every point of the boundary of the base to a common vertex."
Note that the common link between the vertex and the base is a "line". Multiple cylinders of minute differences in diameter do not a cone make.
Poly-cylindrical would seem to be appropriate.
MOO (My Opinion Only),
Matt
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Author: Ken Shaw
Date: 2001-12-07 14:23
Before I wrote my posting last April, I read everything I could find on the Buffet polycylindrical bore. I think it's clear that the R-13 bore is not a pure cone/reverse cone, but rather a "stepped cone" with areas that are cylinders of three sizes, with definite transitions in between. The differences are only a few thousandths of a millimeter, and the small amount of blending at the step points doesn't turn the overall shape into a cone.
On the other hand, the bore probably acts as a cone/reverse cone acoustically, although there are probably complexities caused by the stepping.
While I don't know this, it wouldn't surprise me to learn that, say, Hans Moennig or the Brannens do even more blending to make the bore closer to a pure cone shape.
However, the current Buffet R-13 models, as they come from the factory, definitely have a bore in the upper joint that's a series of cylinders of three sizes. The RC has cylinders of two sizes, and one poster has said that the R-13 A clarinet also has only two sizes.
The final shape is not a true cone or a true sequence of cylinders, though it's closer to a sequence. Geometry mavens undoubtedly have a name for it. Perhaps acousticians do, too. However, since Buffet calls it "polycylindrical," and the clarinet community uses that word to refer to the Buffet bore, my English major instincts say it's best to stick with the familiar word. It's a "term of art" -- a word given a particular meaning and used by specialists to say to other specialists something that would otherwise take a page or two of description.
Best regards.
Ken Shaw
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Author: Don Berger
Date: 2001-12-07 17:29
Well said, Ken, this seems to have a bit of "three blind men describing an elephant" !! Don
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Author: Peter
Date: 2001-12-08 16:18
As Ken (and others) agreed it is "poly-cylindrical."
All, from mathematical, engineering and a literary English perspectives, each individual cylinder cut into the bore would have to be a cone for it to be "polyconical," meaning many cones.
As the design (purportedly) is, in fact, measurably cylindrical in all its individual steps, then it is, poly-cylindrical, regardless of how it may theoretically "act," ie.: as Ken said: "...the bore probably acts as a cone/reverse cone acoustically."
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