 The Clarinet BBoard
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Author: BobD
Date: 2008-07-06 12:07
A search here and on Google reveals a lot of talk about "taper" and "reverse taper" leaving the reader possibly confused. It appears that in the "non-clarinet" world Taper i.e. Regular or Normal Taper....means "going from a larger diameter to a smaller diameter". "Going" can mean: From Top to Bottom or it can mean "in the direction of fluid flow from source to destination". Using this definition, then, a bottle cork has a Regular or Normal taper. If the above is correct then a Reverse Taper would be smaller at the entry end and larger at the exit end i.e. the reverse of a bottle cork.
However, the following is a typical Clarinet World comment:
"The Moennig barrel is based on a reverse cone taper. This taper is usually from .589" tapering to .580". Thus, the lower end of the barrel is smaller than the bore at the upper end of the upper joint."
It appears (to me) that Clarinet World interpretation of the concept of taper is opposite to the Real world. According to Real World terminology a clarinet bell would be said to have a Reverse Taper but Clarinet World would say the bell has a
Regular taper.
Perhaps the (my) confusion is due to the fact that I don't know what a "Reverse Cone Taper" or a Reverse Cone....or even a Cone is.
My post here does not solicit opinions on what a Moennig taper is but, rather, why it is referred to as Reverse or Reverse Cone. A highway traffic cone is smaller at the top than the bottom and an icecream cone is......uh....
Bob Draznik
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Author: clarnibass
Date: 2008-07-06 12:23
I'm just guessing based on what seems logic to me that a reversed cone or reversed taper for a clarinet or clarinet barrel means smaller at the bottom than at the top. This makes sense because it is the opposite of what a cone usually means in woodwinds like oboes and saxophones (or instruments much older than those like horns), which are smaller at the top than at the bottom.
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Author: tictactux ★2017
Date: 2008-07-06 12:33
> Perhaps the (my) confusion is due to the fact that I don't know what a
> "Reverse Cone Taper" or a Reverse Cone....or even a Cone is.
Here's a cone:
Here's a reverse cone:
--
Ben
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Author: Alseg
Date: 2008-07-06 12:34
It is merely a "shorthand" way of conveying the same thing.
If we really got to specifics, I would have to refer to my own tapers as pseudosinosoidal parabolics with variable inflection points....So, "taper" or reverse taper works just fine in print.
Likewise, when looking down a "polycylindrical" bore, I do not see multiple cylinders side by side (like gattling gun)
Former creator of CUSTOM CLARINET TUNING BARRELS by DR. ALLAN SEGAL
-Where the Sound Matters Most(tm)-
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Author: hans
Date: 2008-07-06 15:21
Ben,
Thank you for a good laugh :-)
Regards,
Hans
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Author: Ed Palanker
Date: 2008-07-06 15:24
It may not be perfectly scientific but my impression of a reversed taper barrel has always simply meant that the inside cut of the bore itself was reversed. Instead of going from large to small, or small to large in the taper it’s as if the barrel was upside down, except for the joints of course, otherwise it wouldn’t fit onto the clarinet and mouthpiece. I know that’s rather simple but so am I. ESP www.peabody.jhu.edu/457 (Listen to a little Mozart, Live recording)
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Author: Bassie
Date: 2008-07-06 16:14
Well, a saxophone is a conical instrument. (This is why it overblows an octave instead of a twelfth.)
Modern clarinets tend to be slightly wider at the mouthpiece-end than in the middle. This upper portion of the instrument is then a 'reverse taper'.
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Author: Ryder
Date: 2008-07-06 17:17
wait...........
So what is the GENERAL shape of the clarinet?
polycylindrical?
or conical-cylindrical?
This is such a confusing topic, but one we need to understand. Well not fully, that way barrel, mouthpiece and clarinet manufacturers still have a their secrets.
____________________
Ryder Naymik
San Antonio, Texas
"We pracice the way we want to perform, that way when we perform it's just like we practiced"
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Author: BobD
Date: 2008-07-06 17:21
Thanks everyone for clarifying the issue. On reflection I guess Moennig was thinking of the conical bore of a saxophone( as Clarni says) and the "reverse" of that would be a bore that was larger at the top than at the bottom. Probably better to say, "reverse conical bore" and leave the word taper completely out of the description. ......in other words, the opposite of Ben's illustration.
Bob Draznik
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Author: Bassie
Date: 2008-07-06 22:20
The general shape of the clarinet is a cylinder, like a flute or an organ pipe. But it has gained something of an hourglass characteristic over the years. Compared to things like violins, the clarinet is not a mature instrument and designs are still changing a fair bit as the years go by.
The original reverse taper, as I understand it, was the R13, and was achieved by a series of straight reamers of different sizes, resulting in a 'polycylindrical' bore. I have no real idea whether makers put true cones and curves on their upper joints these days.
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Author: Don Berger
Date: 2008-07-07 00:00
In general, I agree with Bassie and BobD's conclusions on bore geometry and terminology. I recall that Dr. Benade, in his definitive papers, considered the several "Bessel forms", all expanding, cross-sectional designs, concluding that only the cylindrical and conical forms had musical significance, hence, the clarinet/flute and the saxophone/oboe shapes are [nearly] all [the ww's] that survive. Reading my Ency.Brit. Micropedia dissertation on "cone" [the geometric definition] gets quite involved in terminology, may need to consult a "big" Webster also. Since our insts. [even blown cattle horns] are of the "expanding bore" character because of the "fluid-flow" direction, I'd presume that this might/should? be the "normal" configuration, so that the reverse [decreasing bore size] should be called the inverse/reverse. It seems to me that the term "taper" is ?ambiguous?, likely meaning both expanding and contracting, and also true conical and polycyl designs.. Too "wordy", Mark?, hope some of our math-majors will speak up !! Don
Thanx, Mark, Don
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Author: na1965
Date: 2008-07-07 00:53
In geometry a cone is a pyramidal shape with a circular base and the vertex (point) above the base and therfore it is narrower at the top than the base. A cone with a reverse taper would be wider at the top and narrower at the bottom. Since most people prefer ice cream to geometry, we tend to think of cones in the opposite way!
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Author: Mark Charette
Date: 2008-07-07 01:57
Don Berger wrote:
> ...
Just a little birthday greeting to most probably our "oldster" on the list. Don just turned 89 but I'll bet a few of you thought he was still a teenager!
May we enjoy your postings on our BBoard for decades to come!
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Author: Don Berger
Date: 2008-07-07 02:53
Thank You, Mark, its been a great day, I'm planning on more ! One of our fellow "inmates" at our retirement "Village" is past 100, and still "with it". Our Tulsa Community Band has an unusual arr. of H B with Hallelulia [sp?], and ?forced? me [reluctantly?] to acknowledge 89 at a concert !! Very well said, na1965. Don
Thanx, Mark, Don
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Author: Bassie
Date: 2008-07-07 08:10
> only the cylindrical and conical forms had musical significance
Brass instruments tend to have a cylindrical or shallow conical tube with an exponential flare at the end, to make the 'open' end look more exactly like a truly open end through a kind of impedance matching. Presumably the clarinet bell has something of this role, though as most of the notes sound through the tone-holes it must be a secondary effect. Personally I suspect there's something in the weight of the bell that adds to the character of the instrument.
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Author: saxlite
Date: 2008-07-07 17:48
I am curious about Bassie's comment about "saxophones and oboes being conical, therefore overblowing an octave". While certainly this is true, flutes seem to be cylindrical and also overblow an octave as compared to the clarinet which overblows a twelfth. Would appreciate some understanding of this apparent contradiction- thanks.
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Author: Tony Pay ★2017
Date: 2008-07-07 18:23
Saxlite wrote:
>> I am curious about Bassie's comment about "saxophones and oboes being conical, therefore overblowing an octave". While certainly this is true, flutes seem to be cylindrical and also overblow an octave as compared to the clarinet which overblows a twelfth. Would appreciate some understanding of this apparent contradiction.>>
http://test.woodwind.org/Databases/Klarinet/1998/12/000783.txt
...might help.
Tony
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Author: tictactux ★2017
Date: 2008-07-07 18:27
> While certainly this is true, flutes seem to be cylindrical and also overblow an
> octave as compared to the clarinet which overblows a twelfth.
In very simple words - sax and clarinets are tubes that are only open on one end (guess which), the flute is open on both ends (ie also at the lip plate end), same goes for the recorder. For an octave you either need a conical one-ended tube or a cylindrical two-ended tube. Else you get a twelfth.
--
Ben
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Author: Bassie
Date: 2008-07-08 08:40
It took me ages to get my head around /why/ a conical closed tube overblows an octave:
In a /straight closed pipe/ the pressure distribution looks like a sine wave. You need a maximum at the closed end and a minimum at the open end, so you can fit in a quarter wavelength, or 3/4 of a wavelength, or 5/4 of a wavelength... leading to the odd harmonic series of the clarinet (and its curiously low fundamental notes)
In a /straight open pipe/ you need a minimum at both ends, so you can fit in half a wavelength, or a whole wavelength etc.
In a /cone/ the pressure distribution looks like a modified sine wave known as a 'sinc' function. Sinc is defined as sin(x)/x and looks very much like a sine wave except that it doesn't go to zero at zero, but instead has a maximum. So half a wavelength of sinc has a maximum at one end and a minimum at the other. So does a whole wavelength, and so on and so forth. The frequencies at which a cone will resonate turn out to be the same as those of a straight open pipe, though the cone has a pressure maximum at the closed end and a pressure minimum at the open end just like a clarinet.
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