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HP to LP Clarinet Conversion

Steve

Clarinet CE/Moderator
Staff member
CE/Moderator
With the OP i'm curious if other mpcs have the same effect on intonation as the Behn mpc ?

Mouthpieces can make a dramatic effect on intonation.

Mr Fobes has some very nice mouthpieces and barrels. I've had a few go through my shop. I've read his articles in the past and continue to reread articles / books all the time because as one learns more it all makes more sense when things are reread.

After my experiment late last year of creating a "recorder" and making/plugging toneholes (smaller, larger, undercut, placed differently) my next adventure is taking a HP clarinet and attempting to make it low pitch ...

interestingly enough. I just finished a late 1960s R13. The entry and exit bores of the barrel to the Upper joint to the lowerjoint were not in sync and too small per other specimens. This is one of those clarinets where you have to pull out the joints to make the relative segments in-tune.

I so much wanted to correct the entry bore of the joints so see what would happen .. but not on a customers beloved 1 owner R13 .... thus the initial experiments wtih a recorder and now a HP.
 
After my experiment late last year of creating a "recorder" and making/plugging toneholes (smaller, larger, undercut, placed differently) my next adventure is taking a HP clarinet and attempting to make it low pitch ...
I would be very interested to hear what your strategy might be to do this. Obviously you cannot move every tonehole lower. To bring an A=456 pitch instrument down to A=440 would be an enormous challenge. Please keep us posted on this interesting endeavor.

John
 
I would be very interested to hear what your strategy might be to do this. Obviously you cannot move every tonehole lower. To bring an A=456 pitch instrument down to A=440 would be an enormous challenge. Please keep us posted on this interesting endeavor.

John

Gonna start the easy way .. long barrels. Since I can make any length barrel that will be the start.
FYI .. go to the bottom and the HP Buffet Eb is the test instrument.
http://www.clarinetperfection.com/MyClarinets.htm

On another note. I have a Langelais mpc that makes a Noblet 45 flat across the board. it works just fine on an R13 though. Of course I have mpcs that work fine on the Noblet 45 and my R13.
 
Gonna start the easy way .. long barrels. Since I can make any length barrel that will be the start.
FYI .. go to the bottom and the HP Buffet Eb is the test instrument.
http://www.clarinetperfection.com/MyClarinets.htm
That work-around really doesn't work very well, as it's going to be the proportions of the distances between the tone holes that really determines the intonation standard.

Now, I can say that I can make an A=440hz sax play consistently in tune at A=442hz by playing around with the neck and/or mouthpiece, but A=440 to A=457 is almost a half step.

The best strategy for faking a low pitch horn will probably be to either play with the lengths of each joint and/or play with the sizes of the tone holes. Even then, you might have it properly tweaked for one kind of mouthpiece with one kind of reed for one player.
 
I agree. It would almost be easier to transpose everything up a half step, pull the barrel out and lip down.

John
 
But I'm not making a transposition experiment. If that was the case I would just simply use an LP horn.

It's an experiment to see if a HP can be morphed into an LP.

The barrel is a starting point, which is experimentation which I'll be evolving.

I was hoping that a customer was going to send me a HP early Bb Buffet as I have a LP sister. Thus I could measure and compare and determine a more definitive first strategy. but without a LP/HP pair i'll be experimenting for a while. Doing the "can't change" tests later on. I still might opt to ebay a HP early Buffet Bb.
 
That was a lame attempt at humor Steve. I think you will find that the only way to keep the clarinet in tune with itself is to do a combination of bore alterations and tone hole adjustments.

A rule of thumb from Nederveen in his "Acoustical Aspects of Woodwind Instruments" p. 50 states:

"We assume 10 cents to be the threshold of perceptibility . . .From the two separate equations we then find that this corresponds with a 1% change in distance to the (acoustical) top of the instrument, a 10% hole-diameter change or a 20% hole-length change."

Since "short tube" notes are lowered more by increasing barrel length, as you go farther down the clarinet greater changes to the toneholes will be required to keep the pitch relationships constant. For example a tonehole 8 mm from the acoustic top of the instrument would need to be lowered (crescent?) .08 mm to effect a 10 cent change in the pitch while a tonehole 24 mm from the top would need to be lowered .24 mm to effect the same change.

On oboe changes to the position of the tonehole affects primarily the lower octave, and changes to the size of the tonehole affects primarily the upper octave. Whether this is true of the registers of the clarinet, I do not know but I suspect that is the case.

A comparative measurement chart of two clarinets of the same make, one HP and one LP, would be an incredible learning tool---especially if they were a quality brand like Buffet.

John
 
That was a lame attempt at humor Steve.
I tried ... :-D

I think you will find that the only way to keep the clarinet in tune with itself is to do a combination of bore alterations and tone hole adjustments.
Yes, but one has to slowly move into experimentation .. crawl before you walk. reading is one thing but when you start widdling wood it's hard to go back after making a mistake .. plus I don't exactly have a budget ....


A comparative measurement chart of two clarinets of the same make, one HP and one LP, would be an incredible learning tool---especially if they were a quality brand like Buffet.
I know .. there's a HP Bb Buffet on eBay right now .. if it stays low enough I might just go for it or I might just hold off until a HP is in my hands. I'd hate to screw up that Eb even though it is close to useless.
 
Just as an opinion, unless there's a major call for HP to LP conversions, I think it'll just be a rather frustrating exercise. Now, as John mentions, it'd be interesting to get comparisons between the two instruments, that's more a curiosity than anything else.

I'd rather get one of your improved barrels and maybe a bell :).
 
Just as an opinion, unless there's a major call for HP to LP conversions, I think it'll just be a rather frustrating exercise. Now, as John mentions, it'd be interesting to get comparisons between the two instruments, that's more a curiosity than anything else.

I'd rather get one of your improved barrels and maybe a bell :).

curiosity ...... plus i'm not exactly in a rush. may not do anything for 6 mths ... just saying 'ya know. I do like the idea of having a HP & LP first before investing too much tinkering time which is limited anyways.
 
Barrel joint dimensions and LP/HP instruments

There are two items of interest that came up this discoussion and I will try to be as brief and succinct as possible. I was not absolutely clear from Steve's description on his 1960 R-13 where the bores did not match up. (the bottom of the barrel join to the top of the top joint?) In any case, these numbers do not ordinarily match up. A "typical" R-13 Bb(there is definitely variation in this dimension) is about .587"-.589" at the top of the upper joint and usuallly .577-.580" at the end bore of the upper joint. Standard Buffet barrels seems to be running at about .595" right now, which in my opininion does not work with most of the medium large bore mouthpieces that American makers favor.

My barrels are about .588" at the top and .577 at the bottom. The R-13 as designed by Robert Care ca. 1950 is a POLY CYLINDRICAL bore, which means there are several steps in the bore rather that a straight tube ending in a bell flare. Essentially the 3 "cylinders" (in actuallity tapered cylinders) are the barrel, the top joint to about the "A" tone hole and the middle bore to about the G/D tone hole where the bell flare begins. It is fairly typical for Buffet instruments from the 1960s to play rather sharp when attempting to play at 440. so pulling at the middle joint is a good solution.

As to changing an HP instrument to an LP instrument, that would be an exercise in futility. John on this forum makes some excellent points regarding tone hole placement. The other consideration that may seem counter intuitive, is that if you increase the bore size under an existing tone hole you will RAISE ptich, not lower it. This is essentially a form of localized fraising. I suspect that an HP instrument may be slightly shorter than an LP instrument and that the tone holes are either slightly larger or closer together. I do not have an HP and LP of the same maker to do a comparison.
 
A "typical" R-13 Bb(there is definitely variation in this dimension) is about .587"-.589" at the top of the upper joint and usually .577-.580" at the end bore of the upper joint. Standard Buffet barrels seems to be running at about .595" right now, which in my opinion does not work with most of the medium large bore mouthpieces that American makers favor.
Any idea why this is done? Color me very curious.

Oh, and welcome to the forum. :cool:
 
Yes, welcome to the forum Mr. Fobes. As you noticed our new forum members have to be approved first ... though they shouldn't have been able to PM someone - it was to stop a problem where we were having bots PM-spamming people.

But briefly (I'm in the middle of dinner and jazz band) ...

I was curious why the Lower joint entry bore - the bore at the top of the Lower joint was fairly smaller than the Upper joint Exit bore (the bottom of the Upper Joint). This clarinet required the lower joint to be pulled out.

Whereas on another R13 of same vintage the lower joint entry bore was much more similar with the upper joint exit bore and did not require the lower joint to be pulled out.

I don't have the numbers in front of me but will check for them for later.
 
I would also like to welcome Mr. Fobes to the forum. I have been an admirer of your work and products for many years.

You indicated in a previous post that your barrels are .588 at the top and .577 at the bottom. This would produce a very slight reverse taper if I understand the dimensions correctly. Can you describe for us the effect a slight narrowing of the barrel has upon the soundwave, intonation, registers, etc. Thanks.

John
 
This might be a candidate for the old "string in the bore" dodge, just to see what happens. I was always going to experiment with different cord sizes (and textures, just to see if a hard woven shoestring was any different than a piece of loose woven twine), but girls and physics got in the way, and that was that.

A "stringed" clarinet plays down in pitch, in theory far enough to act as an A clarinet. In my experience, it didn't flatten the horn enough to make that come true, but it was a start. It might be enough to drop a HP Bb (or A) horn to LP, and (in any event) is a lot cheaper to try than would be the relocation of tone holes.

(Moving the tone holes sounds like something Chris P would attempt...)
 
I tried the "string in the bore" conversion just now on my "E J Albert Bruxelles" turn of the last century (or slightly earlier) Albert system clarinet. It plays quite well as is at A=456 HZ. The length (less mouthpiece) is 22 5/16th inches. The bore at the top of the upper joint is .565 and at the bottom of the upper joint is .578; no reverse taper here!

The barrel measures 56mm. I use a Selmer C85 120 on it which, though clearly designed in a different era, seems to work fine. I had to enlarge the female mouthpiece tenon socket in the Albert's barrel to accomodate the larger modern mouthpiece tenon size there but the depth of the socket was fine.

Rather than a length of string I inserted a trumpet snake (vinyl coated metal coiled shaft .18" in diameter) which had had the cleaning brush broken off at some time in the distant past into the bore from the bell end. This is just under an area reduction of 10% for the bore cross section at any given point. (9.7% at the lower end of the upper joint; proportionately more at the upper end but just a bit and of course less as the lower joint progressively enlarges in bore)

With the snake inserted to just past the register vent the clarinet played about 10 cents sharp at A=440. ( about A=443 hz) It was surprisingly free of induced tuning anomolies (about the same as it had been at A=456 HZ) through the mid clarion though it became a bit squirrely at the upper end. The altissimo has never been anything to write home about and it remained dismal. The overall sound of the horn was a bit dampened with the insertion- but less than I had expected. The effective bore drop to about .543 makes it a rather small bore clarinet!

While I surely wouldn't consider this as a way to use the horn in a modern setting as a 440 instrument the "full length of the bore volume reduction to lower the overall pitch" was nonetheless surprisingly effective. The consistency over the break from Bb to B was remarkably good. I'll trundle on down to Home Depot tomorrow for a few hardwood dowels of various sizes just to see how close it'll come to 440.
 
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HP to LP

interesting discussion. My local repair tech and I have chatted about this. Lengthening the barrel is step #1 but as noted, this will not ensure the clarinet will play "true to itself" throughout the entire range. You might consider lengthening the barrel AND adding spacers between the 2 body pieces -- this would be a more proportional add (even though still not exactly correct)/

For a "given" location of toneholes, I would expect it's the bore dimensions that are the key determinant --- aka, unless you can change the location, size of the toneholes, the bore dimension would be the key determinant iof pitch ...


Just guessing, but a few thoughts .....
 
Ah, the eternal quest for a clarinet that can be all things to all people.

This has been attempted in the past, but as far as I can determine none of the attempts have been worth the effort. Rather than spend the time and treasure to attempt this, you would be far better served purchasing a decent intermediate horn.

But, that's just me...
 
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