 The Clarinet BBoard
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Author: Koo Young Chung
Date: 2006-09-15 10:55
My R13 has fantastic tone quality, top to bottom except throat Bb.So I had to do something about it.I know there has been literally thousand posts about this and many different solutions for this incurable naughty note.
Using trill key is not practical when you play fast and coverng lower holes to make it resonate better only improves the note marginally. There are different Bb mechanisms out there but none of them will be accepted by majority of players.
I'll skip how I got my solution. It is part luck and part inspiration.
But this is what I did and it cured my R13's stuffiness of throat Bb.
***
I took off the speaker key and removed the small tubing by tapping gently from inside. R13's speaker hole is about 2.x mm. I made this hole
slightly bigger by careful drilling and filing to 3.x mm.
And I put a very small retangular insert into the tubing.It is about x mm and
thickness is 0.x mm.
Koo young Chung
Violin maker
Post Edited (2006-09-18 03:59)
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Author: Gordon (NZ)
Date: 2006-09-15 11:42
This insert idea has often been suggested in the saxophone forum - www.saxontheweb.net Sometimes a length of clarinet flat spring is used.
The effect is probably has something to do with decreasing the turbulence in the flow of air through the vent, hence increasing the flow. http://en.wikipedia.org/wiki/Reynolds_number
Smaller cross-section tubes, with the same fluid velocity, have less turbulence.
I wonder if the insert, without drilling out the hole, would have had the same effect of curing the stuffiness without significant pitch change.
In the sax forum, stretching pantyhose tight over the vent is also suggested.
For you, has this made any difference to tone or pitch of the notes in the top register? That would be my concern, seeing that vent is a compromise used for around 25 different situations.
Post Edited (2006-09-15 11:54)
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Author: Koo Young Chung
Date: 2006-09-15 11:56
I didn't know about sax players try this before.(There's nothing new under the sun)
I didn't noticed any pitch change or degradation of tone quality,if anything
the altissimo notes got better intonation,clarion register no perceptible
change at all and low register ,of course no effect at all.
If you put insert without making hole larger,I think it will get worse because
it constrict the air flow and I'm sure it'll make the Bb note flatter.
I "discovered " this idea accidently but the effect is unbelievably effective.
I wouldn't dare to say it is cured 100% but it seems like 95 % cured.
Any one can try using old horn part if you don't want to possibly mess
up your $4K instrument.
Post Edited (2006-09-15 12:48)
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Author: Synonymous Botch
Date: 2006-09-15 12:05
After the modification, how well are the longest notes in tune?
If you hold down all the keys, and blow the lowest note - does it agree with your tuner? Same keys down, with the register vent open - does that note agree with the tuner?
More importantly, are these notes equally flat or sharp?
I just use the "side" B-flat when possible, employing the lowest trill key.
(I tried the Galper vent for the same reason, and found the 12ths broad.)
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Author: Koo Young Chung
Date: 2006-09-15 12:43
To S.B.
I've been checking the pitches frequently these days even before doing this modification.
I didn't notice ANY differences at all (as much as I can tell.)
The insert covers the vent hole partially and the idea is that you make the total cross-sectional area same before and after.
To Gordon,
I think clar flat spring is too thin if you enlarge the hole a little bit.
Any wood or plastic is ideal because you can fine tune by adjusting the thickness.
Post Edited (2006-09-15 13:57)
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Author: William
Date: 2006-09-15 14:19
Stuffy Bb's--NO PROBLEM!!!! Just play A#'s instead.............
:>)
Seriously, interesting innovation. Perhaps you should patent your idea, produce a one-size-fits-all version of your device and make a lot of money from all of us gizmoholic clarinetists.
(when can I place my order)
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Author: saxlite
Date: 2006-09-15 14:47
I would like to try your idea, but I don't quite understand your modification. You say that you opened the register hole from 2.7 mm to 3.5 mm.....did you make a new register tube of 3.5 mm diameter to fit the larger hole? Or, is it just a hole with the ivory cross piece and no register tube? If you used a tube, was the tube the same length as the original? Can you provide a photo of your new setup?
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Author: Chris P
Date: 2006-09-15 15:07
He drilled out the existing register tube from 2.7mm to 3.5mm, then put it back in the clarinet with the ivory insert.
I'm experimenting with an additional speaker vent in the barrel, pretty much as the Selmer Marchi system. So far I have fitted an insert with a 0.75 hole that does away with using a speaker key completely (except for throat Bb) and the entire range can be played with this vent open all the time.
But unlike the Marchi system I can't get the altissimo E by playing low E (and all other notes upwards) with this vent at the moment.
Former oboe finisher
Howarth of London
1998 - 2010
The opinions I express are my own.
Post Edited (2006-09-15 15:19)
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Author: David Spiegelthal ★2017
Date: 2006-09-15 16:23
What I frequently do that seems to improve the throat Bb is sort of similar in concept: I remove the speaker tube and flare (radius) both ends using a 45-degree countersink (rotated by hand). This has the similar effect of reducing turbulence without adversely affecting intonation or response, in my experience. On the inboard (bore) end of the tube only a very shallow taper is possible, as the tube wall is quite thin there, but on the exit end a somewhat deeper flare can be made. Adding to this a tapered cork pad, most of the stuffiness/hiss can be eliminated from the throat-Bb. Nothing new here...........
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Author: Don Berger
Date: 2006-09-15 16:56
Hi Dave - Please don't downgrade your [possible] invention, at least on the basis of [lack of] novelty [new-ness]. Sounds to me like a "venturi type flow pattern" produced by your special dimensions, also meets the criteria of usefullness and non-obviousness, thereby potentially patentable ! There is not much prior art [known to me] in this narrow field, Marchi and Galper, and perhaps some "incidental disclosures" in comprehensive cl patents and pinch Bb "solutions" such as Stubbins et al. I've been "lurking" in these threads as you know, so just had to speak up. Don
Thanx, Mark, Don
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Author: Vytas
Date: 2006-09-15 17:02
Koo Young,
I've measured hundreds of register key tubes. You have made very sloppy observation and measurement as far as register tube is concern. First of all the register tube has conical shape. The hole inside is reverse cone. If your measurement of 2.7 mm is correct than you had a wrong tube installed. 2.7 mm speaker hole is too small. Have you measured both sides? Reverse taper cone in the register tube is there for a reason.
I think, you've actually screwed-up by drilling the hole to 3.5mm and then got lucky with the insert. Manufactures are trying to solve this throat Bb problem for more that 100 years. Some of them succeeded more than the others. BTW. The throat Bb on my King "Marigaux 350" is perfect and I have no complains how it plays on my R13 #51XXX and Selmer CT Omega. Some measurements of the register key tube are below.
R13 #4899X
Top - 3.40 mm (bore side)
Bottom - 3.15 mm (outside the bore)
Length -12.71 mm
R13 #58XXX
Top - 3.34 mm
Bottom – 2 .99 mm
Length -12.57 mm
R13 #61XXX
Top - 3.33mm
Bottom - 3.00 mm
Length -12.67 mm
R13 #67XXX
Top - 3.34 mm
Bottom – 2 .92 mm
Length -12.76 mm
R13 #934XX
Top - 3.25 mm
Bottom - 3.05 mm
Length -12.73 mm
R13 #103XXX
Top - 3.53 mm
Bottom - 2.95 mm
Length -12.68 mm
R13 #270XXX
Top - 3.32 mm
Bottom - 2.99 mm
Length -12.76 mm
R13 #360XXX
Top - 3.42 mm
Bottom – 3 .06 mm
Length -12.70 mm
Vytas Krass
Professional clarinet technician
Custom clarinet mouthpiece maker
Former professional clarinet player
Post Edited (2006-09-15 18:50)
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Author: Koo Young Chung
Date: 2006-09-15 19:14
To Vytas:
Maybe it was too small.but that's how it came.
I knew that it had taper ,but I couln't drill with taper.
(I'm not sure the inverse taper is critical though.)
Dimension are correct within 0.1 mm.
You are right,I got lucky. But the result is phenomenal.
You have to hear how it sounds!
If the manufactures are doing nice job controlling throat Bb,we wouln't discuss
this thing so many times so long.
I strongly recommend that you try this way and see how much change it makes before belittle someone's new idea.
I'm sure there are many different attempts,but this one sure rank way up there.
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Author: Gordon (NZ)
Date: 2006-09-16 00:39
Koo Young Chung
"You wrote: If you put insert without making hole larger,I think it will get worse because it constrict the air flow and I'm sure it'll make the Bb note flatter."
With respect, I don't think so. Yes, there is a slight reduction in flow because of the reduced cross-sectional area.
However, turbulence in fluid (i.e.including air) flow is HUGELY reduced when the flow is turbulent. Most of us have experienced this.... Take a garden hose with a squirter or sprinkler on the end. Have water running through at full flow. Now if we gradually fold the hose in half, the cross-sectional area can become quite constricted, with almost no reduction in water flow. However there comes a point when the smooth "laminar" flow becomes "turbulent". At this point, there is suddenly a lot of audible noise coming from where the constriction is, and a HUGE reduction in water flow.
If there is turbulence in your vent, for one reason or another - including lack of chamfering as suggested by David S - then your insert reduces it, hence greatly INCREASING the flow, a lot more so than the decrease on account of the reduced area. This phenomenon is sometimes used on very large ducts, by filling the duct with many smaller diameter tubes.
Chris wrote:
"He drilled out the existing register tube from 2.7mm to 3.5mm, then put it back in the clarinet with the ivory insert."
Not really. he concept is to not just reduce put a tube in to reduces the vent diameter again, but to divide the circular cross-section vent into TWO vents, each with SEMI-circular cross-section.
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