Substantiating Evidence That All Trumpet Mouthpieces are Not Equal (or consistent).

In a previous post, I addressed the practice of “Clocking” your mouthpiece (“Clocking” Your Mouthpiece Part #2 – Trumpet Blog (thetrumpetblog.com). At the end of my post, I admitted to the possibility that rotating one’s mouthpiece can and did change the sound as well as a resistance factor. In the same article I admitted that I was originally skeptical of this technique but after trying it myself, I was convinced that the rotation made a difference in the final outcome. I also admitted that I had no idea why this happened.

I recently had the pleasure of visiting with someone who was able to fill in the blanks on this subject. His background in this field more than qualified him as a more knowledgeable expert than I.

I was very pleased to have him share his insight and draw your own opinions as you read his following response.

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Thank you, Bruce, for this kind introduction.

As an engineer I can state that all machines regardless of quality or precision of manufacture exhibit eccentricities during their operation, this is often called Bias.

In other words, and in simple terms, all machines without exception wobble slightly while operating. This can vary from very slight to significant.

This phenomenon was exploited by an engineer, attributed to Charles Coborn, as well as Charles Deville Wells and Joseph Hobson Jagger. The actual engineer who did this realized that roulette wheels are also machines, and each wheel has eccentricity that favors some numbers over others.

He postulated that the favored numbers could be determined over time and as long as there were no changes to the table, the favored numbers would continue to hit more often than the unfavored numbers.

With a small group of accomplices, he notated every roulette number on every table in a casino in Monte Carlo for weeks, and then armed with the logs of every spin logged to the table they had occurred on, he proceeded to bet on the favored numbers for each table and break the bank.

It was impossible to economically remove the eccentricities in roulette wheels that he had exploited so the simple solution was to change the wheels each day, so the favored numbers changed every day making the behavior of the tables unpredictable.

Any mouthpiece created on a lathe which in itself moves eccentrically as all machines do, will have eccentricities created during manufacture. Exactly what these eccentricities are and how they affect the performance of the mouthpiece is unknown and would require further research to establish.

The important consideration here is all eccentricities in a lathe fall within the operating limits of the machine.

A lathe is only calibrated or balanced to operate within its design limits. If the part being fabricated requires more accuracy than the Lathe can deliver, then the Lathe would be operating correctly but the parts produced would vary in some way.

Mouthpieces then by their very nature are carved eccentrically because the device that carves them is itself operating eccentrically while it does the carving of the workpiece but staying within its tolerances.

So why do operatives operating the lathes do not notice any eccentricity in the parts they produce. The answer is casual observation and even measurement with calipers or comparison against a template gauge or cutting die cannot reveal very small variations and imperfections.

Everything in engineering has declared standards, some standards are declared in

ISO 230

ANSI B5.54

VDI/DQG 3441

JIS 6330

This is a whole can of worms when trying to relate the accuracy of positioning of machine tools in a lathe, to the final required accuracy of the finished item. There is always variability here.

In simple terms if a product will not operate correctly if it has an accuracy of less than 0.00001 mm, but the lathe creating it cannot be more accurate than 0.0001 mm then none of the products created by that lathe can meet the acceptable tolerances for the product.

The problem is lathes are not very accurate devices compared to the accuracies that humans can detect.

For example, human beings can detect sight abnormalities and defects of less than one single wavelength of light in a mirror that is hand ground by humans and intended for a telescope.

The question is do we need extreme accuracy when we are dealing with sound and not vision.

Trumpets are a resonant device and resonance is all around us in very large scale and in very small scale and the effects of resonance can be profound and far greater and more noticeable than the device which is resonating.

There are observable resonance anomalies at very large scale in the earth’s crust as indicated by Schumann Resonance Anomalies

There are observable resonance anomalies at very small scale in diffraction gratings

Why can there not also be observable resonance anomalies and effects in the boundary between trumpet and mouthpiece in the audible spectrum.

And if this resonance anomaly interferes with the resonance of the instrument, then the conditions are conducive to affecting the resonance of the whole system by varying the relationship between the parts.

In other words, a mouthpiece resonance anomaly could conceivably affect the resonant performance of the instrument.

A significant and perhaps more important question is this, if a mouthpiece has a slight eccentricity in its construction at let us say a 6 o’clock position, why would rotating the mouthpiece in the receiver modify or modulate the resonance of the instrument. What could conceivably be at work here.

The instrument typically has a brace at the 9 o’clock position and this brace modulates the resonance of the leadpipe and therefore the instrument. The leadpipe is known to be a critical component in the resonance of the instrument. This is one of the considerations of instrument design.

It is not an unreasonable assumption in my view to suggest that even a slight resonance anomaly in the mouthpiece close to the exact location of the leadpipe brace might affect the resonance of the leadpipe when the mouthpiece is rotated.

Let us build upon this by reasoned speculation.

Consider a man sitting on a rating chair holding a heavy weight. The man and the chair constitute a couple. As the chair spins if the man moves the weight further away from the center of rotation or closer to it, the distribution of mass in the couple changes and the rate of spin of the chair/man couple changes.

A mouthpiece and receiver form a couple. And if the distribution of mass in the mouthpiece is not entirely uniform then if the mouthpiece is rotated in the couple, then the behavior of the mouthpiece/receiver couple is affected.

This could easily explain why rotating a mouthpiece in a receiver affects the performance of the entire system and could also explain why rotating a mouthpiece might yield perceptible changes to resonance.

Let us consider the work so far

The usual way of researching a phenomenon is:-

Notice an event.

Consider how this might have occurred.

Test if the event is repeatable.

Envision an experiment to reveal if this event is predictable and controllable.

Trap any possibility of errors having occurred in the experimentation.

Analyse the results then formulate a theory describing the behavior.

It appears to me that an event has been noticed that suggests that mouthpiece rotational positioning can noticeably affect the quality of tone.

It has been considered how this might have occurred

It has been tested to see if is repeatable and found to be so

An experiment has been carried out and it has been found to be both predictable and controllable

I believe there are enough grounds to warrant further, more formal testing to trap any possible errors in the testing that has been conducted so far and to ensure the results seen so far are consistent.

The results so far do appear to support the contention that clocking a mouthpiece can lead to improvements in tone.

Before this work and the results derived from it can be declared conclusive further testing should be conducted.

In my opinion the contention that clocking a mouthpiece can enhance the tone produced by the instrument appears to have merit and so far, stands up to scrutiny.

This is not intended as a paper, and I have not conducted any independent research on this topic it is an opinion based upon widely available information and limited testing by the authors of thetrumpetblog.com

References

Schumann Resonance Anomalies in earthquakes

https://link.springer.com/article/10.1007/s12648-020-01865-6

Resonance Anomalies in the Lamellar Grating

https://www.tandfonline.com/doi/abs/10.1080/713819871?journalCode=tmop19