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yeah- good for you to get it. Less is more ! Its like club head speed in golf, if you tighten up , flex all your muscles and try to kill it, should you actually square up the ball, it goes no farther then when you swing easily. It s about moving air thru the horn and letting your diaphragm support the air stream. I play best , when I breath best. I breath best , when I am relaxed !!

Indeed. Bernoulli's principal at work. For tuba, unlike the higher brass, it's not velocity for the most part, but volume, which translates into amplitude of the wave once it transitions the embouchure and mouthpiece and from Bernoulli's principal to standing wave theory.

What hall were you playing in?

iiipopes wrote:Indeed. Bernoulli's principal at work. For tuba, unlike the higher brass, it's not velocity for the most part, but volume, which translates into amplitude of the wave once it transitions the embouchure and mouthpiece and from Bernoulli's principal to standing wave theory.

huh? You lost me. I understand Bernoull's principals of liquid/gas flow and I understand standing wave theory but 'transitions' from one to the other... nope.

Amplitude is volume.

Also, by definition, a principal applies across the board. What works for tuba works for trumpet since the two instruments are so similar.

So if you can clear this up for me, I'm all into trying understand it. Maybe an engineer can explain it to me. Where's Dr. Young when you need him?

Strangelove wrote:http://books.google.com/books?id=iiCZww ... ts&f=false" target="_blank


Wow.

I didn't find anything about transitions in the article. The article offers a good introduction of Bernoulli but it was the transition from Bernoulli principle to standing wave theory you mentioned that I am unfamiliar with. Can you elaborate on that? Is this a direct mathmathematical transition or a measured ratio or something else entirely?

As air is expelled through the embouchure, a low pressure point is created, and the lips tend to come together. As they come together, flow is impeded, pressure rises, and the lips separate again. The regular repetition of this series of events is what creates the pulses which are the vibrations we call pitch through a brass instrument. That is the aspect of Bernoulli's principle that is applicable to brass playing.

Regarding the transition, the whole point is that after the flow transitions the embouchure, throat and backbore, unlike a carburetor on a motor feeding a matching intake manifold channel, the bore on a brass instrument expands rather quickly, and the velocity drops to practically nil. But because of the pulses of the airflow caused by the vibration of the lips, which are induced by, and the frequency of them, are a function of a combination of the mass and firmness of the embouchure and the velocity of the air over the embouchure, then this sets up the pulses which translate to compressions and rarefactions, or anti-nodes and nodes, in the horn which translate to pitch.

The velocity of air combined with how much lip is in the mouthpiece and how firm the embouchure is all work together to translate to pitch. The volume of air translates to amplitude, or dynamic level.

Remember the misguided experiment where smoke is introduced into the leadpipe of a tuba, then it is timed to see how long it takes to come out the bell? It takes a very long time, and then only whisps at a time, because of the velocity of the air dropping to practically nil after it transitions into the expanding bore of the leadpipe. Yes, it does eventually come out, because all the expelled air into the horn has to go somewhere, but it's not the airflow that makes the instrument resonate pitch. It is the induced compressions and rarefactions, which function in the horn as antinodes and nodes to create the resonances as a function of particular partials of the various lengths of tubing depending on which valves are down, that we call pitch, and that are what we hear out of the instrument.

So the airflow induces the pulses on the embouchure which create pitch, and then it is the resulting resonances from the proper length of tubing determined by what valves are and are not down that transform those pulses into pitch with tone.

Well, I wouldn't necessarily go so far as to say the wrong mouthpiece would make a Baer model sound bad, but the matching of the mechanical impedance of the mouthpiece to both the person and horn is at least of some importance, and matching properly can help everything be more efficient and secure.

The best example of this I have actually sat next to was a Conn 5J that sounded horribly thin with a Bach 18, but sounded great with a Conn Helleberg 120S. Likewise, every horn I've ever played sounds good with some mouthpieces and not with others, and my 186 even sounds better with different mouthpieces for each bell.

And all rely on just what the OP has discovered. Today I had a gig with the Shrine band playing for a mini-circus set up at our Temple for the boys, girls and families of those who live in the area who are receiving treatment at one of the hospitals, and the membership's children, grandchildren, etc. (Yes, among others, we did play Thunder and Blazes!) We played for almost two hours without a break except for an announcement or two between songs outlining what was happening. At one point I was getting fatigued I forgot and started pushing a little too hard. With the extra velocity, my low range immediately started cracking a note here and there. I backed off, focused on keeping a really open oral cavity and "big easy air" as some call it, and everything got broader again, just like it's supposed to. Good thing, too, because right after that "Them Basses" and a couple others that are a good workout, ending with a Dixieland medly, were called up. Without relaxing back into the horn, it would have gotten messy. But instead, it was a great closer.