Solar Bell

Attention!

Look for Robin Rowuk on a future edition of "Mythbusters".



Check your local cable directory for the time and channel in your area.

-cw-

Brekelefuw

In clinics, Bobby Shew explains that by saying you need a pint glass of slow air to play the lower stuff and a shot glass of really fast air for the high stuff. Less air, more speed, or more air, lower speed.

NickD

Ah, Rowuk!

I see what you're driving at.

Cool!

There is another demo that was in the ITG journal in which a trombone moputhpiece was rigged witha plastic membrane is inserted just at the end of the backbore so no air can get through it, but the membrane is acoustically transparent. Then they drill a hole in the side of hte mouthpiece and insert straws of various lengths (and hence various resistances) to allow some flow.

The upshot of the demo is that the air flow doesn't even have to go through the air at all. The argument being made by the authors is that the DC component has but one function - to get the lips vibrating at all.

Don't get me wrong. I am in agreement that the fast air model doesn't really hold up, though that is a growth thing for me. Many years ago I did subscribe to that description. I no longer hold to that thinking. I am using my tongue in a specific way and holding my lips a certain way and I use a certain amount of push from the abs, but I never think of controlling the airspeed any more.

Moore, in the article, does hark to some sort of flow control thing, but I am in the dark as to how to visualize it.

OK, gotta split for now.

Nick

Vulgano Brother

I dunno....resonant chambers on both sides of the lips are one thing, but air speed dies quickly. Take a garden variety syringe, fill it with water, and slowly press the plunger and compare the results to depressing the plunger quickly. There is no thunb over the garden hose trickery going on here, but I'm pretty sure the water exits at different speeds.

Water is not a gas, so let's use a turkey baster and a cat. Invite a local cat to examine the business end of the baster, and slowly depress the bulb. Compare the resulting cat behavior to giving a quick blast.

There was a cool article long ago in the ITG Journal, where the air velocity coming out a trumpet was calculated using a thin soap membrane across the bell of the trumpet, and the the resulting bubble permitted the scientis to calculate the actual air speed (not fast at all, by the way.

It may be, that in truth our air pressure makes the higher notes possible, but it is a heck of a lot easier to tell a student to "blow faster" than urging "more" pressure out of them.

nordlandstrompet

Fast air?

In a car carburator the is a device called "venturi" where the gas dies is mounted. The "venturi's" mission is to give the intake air a higher speed, to be able to let the dies work correct. The venturi is a device which looks like a time glass.

So, what is meant with fast air?

The answer of this might be "venturi".
When your tongue is placed normally in your mouth, there is no venturi. When you lift your tongue up, you are making a venturi which forces the airstream to a higher speed when it passes your tongue. Your lips are also making a venturi, and the more you squeese them together, the smaller the venturi appears, and the smaller the venturi is, the faster the airstream will travel. In your mouthpiece you have a cup which "brakes" the airstream because of its volume, but the airstream will accelerate when it goes through the mouthpiece, and will slow down again when it goes into the leadpipe. The speed of the airstream which comes out of the bell, will be at slow speed, because of the diameter of the belltube. The crossection of your embouchure is e.g. 1mm in dia, and the bell is e.g. 40-50mm. To give an example: Fill your loungs with air, hold your hand in front of your mouth and blow the air out of your fully open mouth, Feel how strong the airflow is. Repeat with your mouth closed and blow the air through one side of your nose. If you use the same pressure when on both methods, the time you use to empty your lounges should be the same, but the nose method should give more pressure, and faster airstream. With faster air, the vibrationspeed of your lips should be higher. OR?

NickD

The soap bubble demo! Here it is.

YouTube - On Breathing for Trumpet

In reviewing this I am disappointed I wasn't clearer when saying the air was moving through the horn slowly. "My bad!" What I meant to say was that the FLOW RATE in liters per second is relatively low. OBVIOUSLY AIR SPEED in meters per second, varies along the length of the horn, the slowest point being at the bell. I just thought the soap bubble is fun here in the context of the discussion.

In this clip I talk about tongue position which is critical to the way I play. I don't talk about fast air, though I allude to controlling air flow. I don't honestly have a better way of describing it, as I am still sorting it all out.

YouTube - Flexibility and Trills

I honestly believe tongue position is important. However, in the context of this discussion, I can't properly explain why, yet. I'll keep an eye on this thread as we are homing in on some great ideas.

TTFN

ND/(&out)

Mark Bradley

Well, I can watch people dunk a basketball all day but it doesn't mean I can do it. I won't stop trying though. Many have probably already seen this but here is Mr. Mendez's take on air:

YouTube - Rafael Mendez - Flight of the Bumble Bee & Mexican Hat Dance

oldlips48

As I try to digest all the information, I have a comment and one question:

Forgive the guitar analogy, but there are two ways to increasy the pitch of a guitar string: make it shorter or increase the tension. Would it be a reasonable analogy to think of the mouthpiece cup width as a string length, therefore the only way to increase the pitch coming from the lips is to increase the tension? Secondly, my totally subjective observation is you must pluck a higher-pitch guitar string a little harder to get a comparable volume. Could this be an analogy to the "fast air" concept (air speed, not air volume)?

My head spins.

My question: Nick, could you enlighten me to the TCE method you mention earlier?

Thanks,
Steve

nordlandstrompet

Guitar anology is ok. I have used carburators.........

I don't think that the width/volume of the mouthpiece will effect the pitch very much, but it will effect the sound. The pitch will mainly be taken care of by the tuning slide, just as when you give a guitar string more or less tension.
When you give a guitar string more tension, and the pitch goes up, you reduce the mass of the string. The length between the anchored points will always be the same, but you are "winching" a part oft the string onto the tuning screw. This means that the string will loose mass, and if you measure the diameter of the string before and after bringing tension to it, you will see that the diameter has shrinked.
In principle this is the same which happens when you push the tuning slide in and make the trumpet’s total length shorter.
Normally, a small volume mpc will make a bright sound, and a large volume mpc will make a mellow/soft sound. (More or less). The small volume mpc will also have a higher compression in the cup (chamber) than the large volume mpc. The pitch can be changed by bending the note up or down, just like bending a guitar string. Therefore, it might be possible that the only way to increase the pitch coming from the lips is to increase the tension of your lips together with increased air speed

Bear

guys, this is great stuff. Blowin' my mind. Someone needs to write up a grant for y'all. One question though... The vibrations of the lips, do they not create the "pitch" in essence, and the speed of the buzz comes from the cross pressure of the lips and air? So what part does the tounge play? Can't someone play a DHC with their tounge on the floor of their mouth? (I can, so I'm lost as to the role of the toungue. For me, if I was that lazer sound, I raise the toungue, darker = lower. Either way, my range is consistent.)