cup shape vs. air flow theory

[Eddie Jeffries]

This is a detailed explanation of something I mentioned in another thread.

It explains an interesting interaction of specific air flow versus specific mouthpiece cup shape.

For the cup shape, consider an extreme.
I once saw a photo of a mouthpiece, perhaps it was one used by Eric M. who used to play with Maynard Ferguson.
The wall of the cup went straight in, then the cup made a 90-degree turn towards the throat, giving the cup vertical wall with flat bottom.
You can visualize how the cup wall meets the cup bottom by looking at a capital letter “L”.
The vertical part of the letter is the cup wall.
The bottom part of the letter is the cup bottom.
The far-right part of the letter bottom is the throat.
If a mirror-image of the “L” could be placed after it, the 2 letters would complete the image of the mouthpiece cup.

Now consider air flow inside the cup.
Most players are born with either a downstream embouchure or an upstream embouchure.
Go to
http://www.magikflute.com/airstreamdynamics/index2.htm
Scroll to the bottom of the page.
The two graphics show air flow for downstream embouchures and upstream embouchures.
Click on the images to enlarge.
I will speak of downstream embouchures in this post just to keep it simple,
but the same thing applies to upstream embouchures if you just turn it up-side down.
When the player is playing low notes, the air stream is aimed mostly towards the throat.
When the player plays middle range, the air flow is hitting a little bit up the cup wall.
When the player plays high notes, the air flow is hitting higher up the cup wall, closer to the rim.

Now that we’ve established the basics, consider how the air flow interacts with the mouthpiece cup that is shaped like “L with vertical walls and flat bottom.
When the player plays a low note, the distance from lips to cup bottom is distance A.
When the player plays a high note, the distance from lips to cup wall is also distance A.
But when the player plays midrange, the air flow is directed diagonally downward, at a 45 degree angle downward, into the far bottom corner of the “L”, for a distance of A + 20 percent (just to make up an arbitrary figure for the longer distance).
That means that the player will feel greater support in the low register and in the upper register than in the middle register.

You might think that this is irrelevant to most players because almost nobody plays a mouthpiece with vertical wall and flat bottom shaped like an “L”.
But the theory also applies to any “U” shaped cup in which the air flow for middle range must travel a longer distance than for lower register and upper register.
That sudden 90-degree turn might be missing, might be rounded, but a vertical wall with a flat bottom will probably cause the air flow for middle range to travel a farther distance.
For many people that extra distance for the air flow in middle register might not be any problem at all.
But what if some players have their A above the staff falsetto break happen at exactly the point where their air flow is hitting that far corner of an “L” shaped cup?
That double whammy might cause problems.

Just something to think about.

Also consider the air flow in a deep "V" cup.
As the player plays higher and higher, the player uniformly feels more and more support.
Because for low notes the distance from lips to bottom of the cup is A,
while for middle range the distance from lips to cup wall is less than A,
while for high notes the distance from lips to cup wall is even less than for middle range.
_________________
eddiejeffries@hotmail.com

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[VetPsychWars]

Interesting theory, I suppose... but the actual air flow is pretty low. All it's there for is vibrating your lips.

The classic trick is to watch a smoker play. The smoke inhaled by the player takes many seconds to exit the bell. Blowing harder doesn't make it come out any faster.

Tom
_________________
1950 Buescher Lightweight 400 Trumpet
1949 Buescher 400 Trumpet
1939 Buescher 400 Cornet
GR65M, GR65 Cor #1

[bg]

What causes the change in partials is the angle of refraction, from the point targeted in the cup to the entrance to the throat. The distance from the player's lips to the wall of the cup is irrelevant.
_________________
Brad Goode
www.bradgoode.com

[Eddie Jeffries]

[bg]

Ah, good point. I'm going see if I can fin a weird mouthpiece like the one you described, and test this out.
_________________
Brad Goode
www.bradgoode.com

[VetPsychWars]

[razeontherock]