 The Clarinet BBoard
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Author: Dan Shusta
Date: 2006-04-11 04:15
I was always curious as to how much pressure was being exerted on the inside walls of my mouth, so...I decided to measure it.
What I did was take an ASHCROFT air pressure gauge, hooked it up to a 1/4" clear plastic tubing and carefully inserted both the tubing and the mouthpiece into my mouth.
I started out with a Brad Behn "Overture" mpc which has around a 1.06mm opening and a 34 facing. To begin any sound at all, the air pressure had to be right around 4.3 oz/sq in. After the tone was started, I could reduce the pressure to 4.0 oz/sq in and it would still hold. Any lower than that and the sound was gone.
I decided to try a Morgan Protone with a 1.15mm tip opening and a 32 facing length. To get the tone started at all, I had to increase the pressure to 5.7 oz/sq in.
All of this was done on an open "G" note using a Mitchell Lurie #2 reed on a Conn 16 clarinet.
What I also found interesting was playing a low "F" note. The pressure reading to begin the note was precisely the same as an open "G".
The sound intensity would increase up until around 7 oz/sq in and basically stayed the same all the way up to 13 oz/sq in. (which was as high as I could comfortably go).
I think this might be an interesting way to compare efficiency of different mouthpieces as well as different barrel designs.
I'm not sure if this has any value to anyone else, but I found it interesting.
Post Edited (2006-04-11 05:39)
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Author: pewd
Date: 2006-04-11 04:29
thats a facinating experiment.
have you tried it with different strengh reeds?
- Paul Dods
Dallas, Texas
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Author: Dan Shusta
Date: 2006-04-11 04:37
Hi Paul,
No, I haven't and I think it would be quite fascinating to increase the reed strength by 1/2 steps and see how the pressure goes up.
I thought up this method because with embouchure dystonia, I'm looking for a mpc/reed/barrel/clarinet body combination that produces a minimal amount of back pressure so I can comfortably play again and needed something that gave me difinitive, measureable results that could be repeated over and over again. To me, this eliminates any guessing that may possibly go on when comparing various pieces of equipment.
Post Edited (2006-04-11 04:42)
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Author: pewd
Date: 2006-04-11 05:05
i think it would be interesting to try an entire box of reeds, comparing the results ; then try the again after break in.
plus we know some barrels are more 'resistant', others are descrbed as 'free blowing'
guess i'll have to find a pressure gauge and play around this summer
- Paul Dods
Dallas, Texas
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Author: Bob Phillips
Date: 2006-04-11 16:19
You are doing a great thing. I hope you continue to experiment/test and to report what you learn.
Thank you.
Bob Phillips
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Author: Cuisleannach
Date: 2006-04-11 18:25
I don't know if he's still doing it, but Doug Miller at Appalachian State University was doing some really incredible work using an artificial embouchure. He had a box that he could pressurize that he would put a clarinet inside of, sealed at the barrel with a collar, where he had constructed an embouchure using dentures. He would close the holes of the clarinet with stoppers and would shine a bright light up the clarinet where he placed a light sensor to determine the opening and closing of the reed. This was back in '86 or '87 when computers were first becoming popular.
He had apparently needed a Doctorate quickly so he picked up a Ph.D. at UNC-Greensboro (this was before UNC-G had a DMA program) and his dissertation on this stuff was the fattest dissertation in the entire UNC-G library.
Wonder what he'd have to say about all of this.
-Randy
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Author: Bartleby
Date: 2006-04-12 08:19
I'm pleased that Dan Shusta is once again posting. I always find what he has to say informative and interesting. What is embouchure dystonia exactly?
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Author: Dan Shusta
Date: 2006-04-12 22:08
Bob & Bartleby,
Thank you both for your kinds words. I did some more experimenting last night and the results were quite astonishing. I need to duplicate the experiments before I post the results.
Concerning embouchure dystonia, you might find the following link informative: http://www.dystonia-foundation.org/defined/emb.asp
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Author: Dan Shusta
Date: 2006-04-13 03:22
I did some more testing after I came home from work and determined the following when using a refaced H-Couf 2* mpc with a Legere student #2 reed:
1) The backpressure did not change when I went from a Rovner Dark to a Rovner Light and then to a Luyben plastic ligature. I was expecting some differences but that didn't materialize. All I could observe was that the sound texture and response characteristics changed as I allowed the reed to vibrate more freely.
2) The backpressure was constant whether I played a G3, G4, or clarion G5. This kind of surprised me because the chalemeau always seemed so easy to play while the clarion seemed to require more effort from me. Now my pressure gauge tells me that the backpressure is the same. So the only thing I can surmise is that the upper clarion and altissimo ranges demand a firm embouchure coupled with a focused air stream. You can't fudge it in this area as one can in the chalemeau. And, according to what I've read from several sources about embouchure is that it needs to be firm and fixed whether in the chalemeau, clarion or altissimo areas. Perhaps it seemed easier because chalemeau tone prodution could still be easily produced even with a looser embouchure and a relatively unfocused air stream.
Freeblowing mouthpieces:
I've played a few that were advertised as "freeblowing" and even "very free blowing" and found them to be rather resistant for me. So...what this taught me is that freeblowing is similar to bright or dark sound qualities--it's different for each individual. What is freeblowing to one person may be resistant to another and what seems resistant to one may be experienced as freeblowing to someone else. It's a personal, subjective determination which may very well be determined by a person's embouchure development.
I also tested another mpc from a refacer which was specially modified to be as free blowing as possible. When I measured the backpressure...it was the same as my other closed tip, 34 facing length mpcs.
So...perhaps 3.5 to 4oz/sq in. may be as low as is possible. I suspect that a longer facing with a relatively closed tip may initially reduce the backpressure with a softer reed but since a stronger reed is usually required, the backpressure will again go back up when a stiffer reed is installed.
Another thing that just came into my mind is high output mpc efficiency which could possibly be construed as a freeblowing mpc. What I mean by this is that I have experienced a certain mpc that produced a louder sound for the same input pressure requirements. Because the output is louder to the ear, I believe it's possible to "mask" the effort involved leading to the belief that the mpc appears to be more freeblowing than others. Another way to state this is: two mpcs may have the exact same backpressure with one producing a louder output than the other. The lower output mpc might be considered "resistant" while the higher output/louder mpc might be considered "freeblowing". I reason this because the lower output mpc will require more effort to equal the volume of the higher output mpc and this means more backpressure will be involved. A bafle/bore design that yields a louder output simply allows a player to exert less effort to produce a desired loudness level.
All of the above are strickly my opinions. I'm principally a hobbyist so please keep that in mind.
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Author: Don Berger
Date: 2006-04-13 13:14
Hi Dan, I echo the above "kudos", and have followed along, with some analysis effort, to consider what is involved, here. A thot, can one calculate/determine the location of nodes/antinodes in our cl tubes for differing notes for some max/min pressures? This is from my none-too-clear, AM coffee-drinking time, regards, Don
Thanx, Mark, Don
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