Does a large bore horn take more air?

Dr GO

@Kehaulani said in Does a large bore horn take more air?:

So, if I buy a medium-bore Getzen and a large-bore Getzen, and a medium-bore Schilke and a large-bore Schilke, will the medium-bore horns be have certain characteristics that separate them from their large-bore counterparts?

So this IS for sure: If you buy both a medium and large-bore Getzen AND Schilke, the companies of Getzen and Schilke will definitely profit!

What! No rubber lips or rubber bladders!
It looks like Artificial Rhonda needs to go back into her suitcase until more lenient legislation can be passed. Just damned. I was starting to feel that she was beginning to like me for who I am.

Dr GO

@Dr-Mark said in Does a large bore horn take more air?:

What! No rubber lips or rubber bladders!
It looks like Artificial Rhonda needs to go back into her suitcase until more lenient legislation can be passed. Just damned. I was starting to feel that she was beginning to like me for who I am.

It's my guess she rubbered you the wrong way!

Tobylou8

@Dr-GO said in Does a large bore horn take more air?:

@Dr-Mark said in Does a large bore horn take more air?:

What! No rubber lips or rubber bladders!
It looks like Artificial Rhonda needs to go back into her suitcase until more lenient legislation can be passed. Just damned. I was starting to feel that she was beginning to like me for who I am.

It's my guess she rubbered you the wrong way!

That remark is a little condomscending and also phallusious.

@Dirk020 said in Does a large bore horn take more air?:

No, this does not help: Explain me the rich, flamboyant timbre and the higher volume of a Conn Connstellation.

Hi Dirk020,
As for explaining, I can't. These are the words of the Yamaha Corp.
I owned a Connstellation in high school and it was a fine horn and tank built for rugged use. When we use words like rich and flamboyant that could be construed as how a particular musician plays and not so much the horn.
Example: Maynard Ferguson with a 1965 Bundy Bb trumpet would sound flamboyant. From a physics perspective, the trumpet is what's known as a "known system" in that science knows how the thing works. When asking why does this medium bore horn play in a rich, flamboyant manner. Well, there are more variables at play than just the inside diameter of the second valve slide. There's the mouthpipe taper, where the braces are placed, the flair of the bell, and acclimation. Possibly the biggest noticeable factor is when a person goes from a large bore to a medium or small bore. If a person who plays a small or medium bore trumpet buys a large bore trumpet off of ebay having never tried it, there is often a period of acclimation one usually goes through before they fit with the horn. I wouldn't go as far as saying bore means nothing. The bore size coupled with several other factors will determine if the person acclimates to the horn quickly or not. I'm use to a medium bore Strad Bb & C and a large bore MF Horn. Since I had the MF Horn before the medium bores, I initially found the medium bores easier to play requiring less effort. Could that be simply be the result of the superior quality of Bach when compared to the Holton MF Horn? Possibly. Solder or better stated, poor quality soldering and shoddy construction can also have an effect.
As for the air I use (now that I've acclimated) it is just enough to get the horn started. I'm of the belief that the hardest thing is to get the trumpet started. Once it's started, the thing almost runs on it's own but it runs on air since we can not voluntarily flap our lips at the rates needed. That's why I tell students to think of the tongue as something that merely interrupt the air flow and doesn't necessarily stop the air flow (ta vs tat).
In the beginning, there appears to be a difference in the air needed when comparing large to medium bore but we become acclimated with exposure.
On a closing note about acclimation I'll leave you with a public service announcement:
Acclimation can kill. When a person smells natural gas in their home, it needs to be investigated and the windows opened asap. Why? Our sense of smell acclimates quickly and soon the person will not smell the gas even though the gas is still there.

This post is deleted!

Dirk020

@FranklinD said in Does a large bore horn take more air?: the problem of large bore horns is that you have to play them more efficient, when that's ok and there is found a balance (resistance) in horn, mouthpiece cup, throat and backbore, the differences in air flow will be minimal.

But still that doesn't explain why my Getzen Eterna 900 LB from early 90's doesn't take more air than my Getzen Severinsen ML from the 70's, or that my Conn 18B Director M bore has the same 'feel' like my Getzen Capri ML bore

All trumpets played with the same mouthpiece

I think the biggest factor in how much air a horn takes is the shape of the bell (72 ish or 37 ish) or/and the venturi in the lead pipe, not the bore size

ROWUK

@Kehaulani said in Does a large bore horn take more air?:

Science aside, , I wonder if instrument makers don't use the bore sizes as matters of classifications, within their own relative results. That horns aren't built with certain characteristics that fall within the bore-size classifications. And these characteristics apply to these given classifications regardless of how it's done?

Man, that's hard to express what I want to say! My point is that, within a given make, do the terms include certain characteristics that show the results and not necessarily the how.

So, if I buy a medium-bore Getzen and a large-bore Getzen, and a medium-bore Schilke and a large-bore Schilke, will the medium-bore horns be have certain characteristics that separate them from their large-bore counterparts?

This was certainly the way that they were built before the Xeno (with the exception of the Bach ML Vindabona). If you want to reduce the amount of „air“ required in a large bore Bach, remove the bell brace next to the tuning slide. Optionally, one could purchase the models with a reversed tuning slide. There the brace is closer to the valve block. More energy escapes through the bell, we hear ourselves better. We fool ourselves into believing that we need less air.

One more time: moving air is ONLY necessary to get the lips vibrating and lubricate them so that the standing wave can be maintained. We are NOT talking about the physical act of filling a trumpet up with air (it is already full) or about fluid dynamics blowing air through a specific pipe size.

If we want to measure how much air the trumpet needs (or better, how inefficient our embouchure is), hold long tones out. Write down when you run out of air. Repeat 25 times for statistical relevance and then try the next instrument.

grune

Very interesting discussion. I have not played all trumpets, nor all mouthpieces, ever produced. For those I have played, I find the mouthpiece is the determining factor for all aspects: particularly for the volume of air I feel I need in my lungs. For horns, inconsistent: some M bore have been difficult to play, and some ML bore have been easier to play. Probing my memory from long ago, I recall the medium bore horns had overall a brighter timbre than the large bore, when the same mouthpiece was used for all.

grune

Excuse, if this link is posted somewhere else. It's a scientist's explanation of no air.

@ROWUK said in Does a large bore horn take more air?:

moving air is ONLY necessary to get the lips vibrating and lubricate them so that the standing wave can be maintained.

Exactly

Kehaulani

ROWUK said "Moving air is ONLY necessary to get the lips vibrating . . "

Well, how do you get the lips to continue vibrating? Don't you need air for that, too?

Dr GO

@Kehaulani said in Does a large bore horn take more air?:

ROWUK said "Moving air is ONLY necessary to get the lips vibrating . . "

Well, how do you get the lips to continue vibrating? Don't you need air for that, too?

No. You need oxygen, glucose and ATP to do this.

grune

@Dr-GO

Hi Grune,
Yes! Harbaugh's masterclass is very good and strips away a lot of the myths about how a trumpet works. Excellent post.

@Kehaulani said in Does a large bore horn take more air?:

Well, how do you get the lips to continue vibrating? Don't you need air for that, too?

Hi Kehaulani,
Hopefully this will help. This is a small quote from Harbaugh (The guy in the video posted by Grune) quoting from a July 1973 Scientific American Magazine;
The continuation of the lips oscillating is based on the fact that the lips move sympathetic to the standing wave. We don't have to make the lips go.
Your second question asks if air is needed to do this.
Yes, if you're a human trying to play trumpet but we never force the air.

ROWUK

@Kehaulani
The lips need "air" to float on. The horn takes care of the "sympathetic" vibrations. The "problem" is that when we play higher and louder we need a mechanism - that is lip tension. To compensate for that increased tension, we must blow harder to keep the lips in a suspended state where they vibrate sympathetically.

Perhaps it is useful to think about the lips not as a vibrating "reed", rather a "massive" damping unit with a soft/flexible surface. When we buzz, we simply match pressure and tension. The lips open and close like a switch.

Kehaulani

@ROWUK -

Well said
.

grune

Well, allow me to have a go at this, please. Correct me if incorrect. Simplistic...

The question is: do I need more air for a larger bore? The answer: it depends.

Why: Boyle’s Principle. Pressure and volume have an inverse function. If volume increases, pressure decreases.

Why is this relevant? Our ears. Our ears respond to 2 factors only: pressure and vibration. Our ears transform pressure and vibration into a signal to our brain, and our brain interprets this signal as sound.

So, to produce a sound from a trumpet, we need pressure and vibration. So how to do?

First, some basics.

A trumpet is filled with ambient air, and air has mass, and thus the ambient air will have an inertial resistance to change.
To produce a sound, that air must be disturbed; i.e perturbed, which results in perturbations.
When the perturbations repeat consistently in cycles over a unit of time, they become vibrations, and we call this a frequency.
When we increase the pressure of the perturbations within the trumpet, we increase the potential energy of those perturbations; and when that energy is released at the end of the trumpet (the bell), we hear this release of increased pressure as an increase in amplitude (loud).
No frequency, no sound. The source and means of frequency is our lips.
No pressure, no sound. The source and means of pressure is the air from our lungs applied to the ambient air inside the trumpet.

Q1. So, do WE need air to make a sound?
A1. YES. Why? The air we push out from our lungs vibrates our lips. No air across our lips, no vibration. Try vibrating your lips without blowing air through them.

Q2. Does the trumpet need extra air to make a sound?
A2. NO. Why? The trumpet is already filled with ambient air. It needs a perturbation and a pressure to get that air to vibrate and produce the sound we hear.

Q3. So why do we see almost no air flowing out of the horn, when we use the smoke method? After all, when we ‘blow’ into the mouthpiece, we feel the release of air from the mouthpiece (m/p). Why is the bell output different from the m/p input (ie why the smoke test shows near zero air flow)?

A3. The key is Volume.
(a) First, we need to know exactly what occurs when air is vibrated at a specific frequency.
A wave is created, having nodes and antinodes. Textbooks illustrate this as a 'sine wave'; but this is incorrect, actually. Both the sine and cosine waves should be shown graphically, sort of like this … ∞∞∞ (I am trying to keep the physics to a minimum).
Why is this important? Because this is how the wave forms inside the trumpet, what exits, and what you hear. What we hear is the antinode, because this is the amplitude: the node has zero amplitude, but maximum pressure. The node must form at the bell: thus the bell shape and volume are critical for sound.
(b) If you blow directly into the lead pipe, you will feel air flow out of the bell (but no pitch). But the outflow will very be very much slower than what you inflow, and it will have much less force (pressure). The reason is simple; volume. As volume increases, pressure must decrease. If the outflow point has a much greater area than the inflow point, the flow from input to output will be very much reduced. The analogy is using a garden hose to fill an outdoor pool. Only a very small volume of water can be pumped through a garden hose, but with high pressure the flow velocity can be very high. If a small volume container is filled, the fill rate is rapid. But try to fill a pool, and the fill rate is very slow. The reason is volume. To prevent overflow, the pool may have an exit port. If the exit port is very much larger in area than the hose nozzle, the flow and pressure of water exiting the pool will be very slow and very low.
(c) So with Volume, Pressure, Velocity, Frequency, we can now comprehend our trumpet and our interaction.
(i) We fill the m/p with a volume of air, moving at some velocity, and vibrating at some frequency. The m/p exit hole is about 3mm. The cup width/depth varies greatly, but let’s peg at 16mm x 8mm. If the bowl is semi-spherical, the max volume will be 2.15ml. The air exiting the m/p will have a noticeable pressure and velocity.
(ii) As our air flows through the trumpet, it must flow through an ever increasing volume. Two results: the pressure decreases; and the wave from the m/p elongates and drops in frequency. If the exit diameter at the bell is 70mm, this alone will account for a reduction of over 20x the input pressure. When we consider the volume of the horn to the m/p volume, the scale factor is huge. Thus the combined factors result in a very low volume and low pressure of air exiting the horn: the resulting air flow may be <1% of the input. Thus we perceive almost zero effects for the smoke test.

Q4. So what about sound volume? Why must I blow harder to get more sound volume? Notice: we are talking about “sound volume” (ie Amplitude) exiting the horn, not physical “air volume”.
A4. Pressure. (physics: the node is point of maximum pressure, thus the antinode is the least pressure). Amplitude is the antinode. Thus for a max antinode, we must have a max node (pressure). We create pressure by blowing air into a vessel (m/p) that is less in volume than the feedstock volume (our lungs). The more pressure we create, the more resulting amplitude.

Q5. Ok. But what about the high notes? Why do these require more effort than the lower notes?
A5. 2 reasons.
(i) Our bodies are very limited in capacity. Our lips are extremely limited and weak: in “natural” state, they are simply not engineered to vibrate at high tension to create high frequency vibrations. We must train our lips/embouchure into a very unnatural state. This requires effort to develop and to apply on demand.
(ii) High notes result from high frequencies exiting the horn. A high frequency requires many times more nodes than a low frequency. Nodes result from pressure. Thus as frequency increases, we must apply more air pressure to create the nodes AND we must increase the tension in our embouchure. The combined factors result in an exponential function: ever increasing tension and pressure.

Q6. Bore. How does the bore of the trumpet factor into all this?
A6. Complicated. The bore relates to the diameter of the tubing at valve #2. In theory, a larger diameter tube will have volume greater than a smaller diameter. But this does not mean a trumpet of L bore will have an overall volume greater than one of ML bore: the bell shape and length is a significant factor to overall volume, and thus an L bore horn can be equal in overall volume to an ML bore horn, and vice versa. Added to this, is the internal resistance of each horn, which is in itself a very complicated aspect to analyse: lead pipe taper; thickness of tubes; radius of bends; bell taper and flare; and more are all factors. Added to this is “dual bore”, where the connection to the bell is usually larger than the rated bore: which creates a lower pressure point within the horn, and presumably this results in lesser internal resistance.

So does a larger bore horn require more air? The honest answer is “it depends”.

I hope this long winded post has not bored too many people.

@grune that impresses me. I'm ready to believe you. I'm no scientist and what you write seems logical to me. However I'm wondering about something related. What about size of bell flare relative to apparent loudness in relation to the same lip produced vibration and volume of air? What if a smaller bore horn had a larger bell flare than a larger bore horn with a smaller bell flare? Would that compensate in fullness or loudness of sound with the same volume of air to produce a like heard result?