This document is primarily intended for trumpet players that have properly practiced trumpet for at least one hour a day for a minimum of 30 total days in their lifetime.
Generally: New and inexperienced players would benefit by starting with the most playable and inexpensive Bach 3C, 5C, or 7C equivalent mouthpiece available to them, until achieving proficiency with the fundamentals of the instrument.
The Proper Selection of Cup Mouthpieces
By Jody C. Hall, Ph. D, Chief Acoustical Engineer of the Conn Corporation (1963, Another Conn Educational Series Publication). Includes content from additional sources.
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EDITOR’S NOTE: The majority of this archived content was originally written and published in September 1963 by Jody C. Hall, Ph. D., Chief Acoustical Engineer of the Conn Corporation. This web version references an original printed copy of this publication as physically obtained by the admins of the trumpet.cloud project. This version has been modernized and very lightly (but tastefully) updated to represent modern technical display capabilities, and integrates additional notes from generally recognized sources. Although the copyright for the original publication of Part One from A654850 ("The Proper Selection of Cup Mouthpieces") was evidently not renewed during the permitted renewal period of 09/25/1990—09/25/1991, this content nevertheless incorporates transformative fair uses of various educational publications and is made available solely for noncommercial research and discussion purposes. |
ACOUSTICAL ASPECTS OF CUP MOUTHPIECES
One of the most important decisions a wind instrument performer must make is the selection of a mouthpiece. Yet he always has had to make that decision with very little information, guidance, or concrete evidence. The usual process of selection has been a combination of trial and error, chasing down rumors of the "perfect" mouthpiece, and listening to the advice and experiences of other musicians. The latter activity has led to many arguments, for the relative merits of various mouthpieces are sometimes hotly debated.
In order to provide a logical, scientific guide for the selection of a mouthpiece it is necessary first to determine the areas of agreement and disagreement among musicians. Then, using objective, experimental evidence, it is necessary to determine the reasons for such agreement or disagreement.
AREAS OF AGREEMENT
It is agreed by nearly 100% of all musicians who play cup mouthpiece instruments that a "large" mouthpiece requires "more air to fill", more "breath support", and greater embouchure development, especially for playing the high register or for extended periods of time. It is also relatively well agreed that a "large" mouthpiece produces a "darker" or "more full", "rounder", or more "Teutonic", type of sound. The "large" mouthpiece also tends to flatten the entire instrument.
On the other hand, it is generally agreed that a "small" mouthpiece requires less air, less embouchure development, has an easier high register, a "brighter" sound, "smaller" or at least "more centered" sound, and sharpens the instrument. (Note: the items which add up to our "large" and "small" mouthpieces will be discussed later.)
Almost the only basic disagreement with the above statements is by those players who do not separate embouchure development from the characteristics of the mouthpiece itself. For instance, a player can develop the embouchure to the point that he can play sharp with a "large" mouthpiece, or can play a "larger" mouthpiece with more ease than a "small" one. Any other disagreement usually is the result of confusion as to what constitutes a "large" or "small" mouthpiece.
The difference in response and intonation between a "large" mouthpiece and a "small" mouthpiece is shown clearly in Figure 1.
| FIGURE 1: LARGE VS. SMALL MOUTHPIECE Intonation shown as number of cents that large mouthpiece is different from small one. |
These resonance curves are measurements of the reaction of a trumpet to an electronically-produced sound, with no player. Note that with the smaller mouthpiece, the complete instrument reacts with more resonance on the higher notes. (The higher the peak, the more the resonance). Thus, with the smaller mouthpiece, the instrument provides more assistance to the player in the high register. Because of the contrast in the amount of resonance (more adjustment required on part of the player) the low register may be more difficult for the player even though the resonance on low "C" is unchanged. Also, with the "larger" mouthpiece, the instrument tends to be flatter, though the extreme high register in this case is a trifle sharper. (The reason for this high register sharpness will be shown later). Intonation is shown in the table as the number of cents that the larger mouthpiece is flatter or sharper than the small one.
It is easy to see why players generally agree as to "large" and "small" since the difference between a "large" and "small" mouthpiece can be measured so clearly with electronic means.
In spite of the seeming basic agreement among musicians where extremes from "small" to "large" are involved, there is much disagreement as to degree, manner, and causes of differences. In order to understand why these disagreements exist, it is necessary to understand the functions of the mouthpiece.
AREAS OF DISAGREEMENT
1. The primary reason for disagreement among musicians’ ratings of mouthpieces is the personal factor. Each player rates a mouthpiece according to his personal requirements, which differ from person to person. The individual musician is actually an acoustical part of the instrument.
2. It has been pointed out that agreement is rather common as to the effect of "large" or "small". However, a mouthpiece is not just "large" or "small", but is a combination of several factors. The degree and manner in which each of those factors contribute to our "coupling device" leads to misunderstanding. In order to analyze the effect of mouthpiece factors individually and in combination, it is necessary first to determine a common vocabulary.
FUNCTIONS OF THE MOUTHPIECE
The mouthpiece is primarily a coupling device between the instrument and the player, as seen in Figure 2.
| FIGURE 2: PLAYER, MOUTHPIECE, INSTRUMENT COMBINATION |
When several musicians play the same instrument and mouthpiece, each individual produces a different timbre. This personal factor is the result of a combination of such things as the embouchure (including the manner in which the lips are held, the size and texture of the lips, etc.), the size and shape of the oral cavity, the manner of breathing, the manner in which the instrument is held (including pressure on the lips, amount of mouthpiece on each lip, etc.), and the concept of each musician.
Suppose two musicians had an identical concept of tone and were trying to produce an identical end product, but one musician’s sound was "more brilliant" than the other. Those two players could produce matched tones by using different mouthpieces, each suitable to their individual requirements.
It has been proven that musicians differ in their intonation patterns when playing the same instrument and mouthpiece, see Figure 3.
| FIGURE 3: INTONATION PRODUCED BY FIVE PLAYERS USING THE SAME INSTRUMENT (Courtesy of John Webster) |
With mouthpieces individually tailored to each person’s needs, it would be much easier for the players represented in Figure 3 to play in tune with each other.
These individual differences in tone quality and intonation are basic and inherent. It is true that a fine player will be more likely to match his sound and intonation to the musical demands than will an inexperienced musician. However, a mouthpiece which properly couples the musician to the instrument will aid that matching process by decreasing the amount of necessary adjustment.
The lips vibrate in a very complex manner during cup mouthpiece performance. High speed motion pictures show that they vibrate much more like the larynx than like a violin string. However, just as a violin string needs definite ends, or termination points, in order to establish a precise vibration, so do the lips. One function of the mouthpiece is to provide a rim on which the lips must rest comfortably, with a definite termination point for the lip vibration at the inner edge of the rim. However, the mouthpiece inner rim must also provide a shape which facilitates changing of the frequency of the vibration of the lips, and it must also provide room for the excursion of the lips into the mouthpiece during vibration. The demands on this shape will vary according to the individual.
In summary:
The mouthpiece is an individual coupling device which matches the personal characteristics of the player with the characteristics of the instrument, encourages lip vibration in all registers, and facilitates the production of a timbre, intonation, and musical effect within the concept of the performer.
THE PARTS OF A MOUTHPIECE
Figure 4 shows a cross section of a trumpet mouthpiece with the various parts of the mouthpiece identified.
| FIGURE 4. TRUMPET MOUTHPIECE CROSS SECTION |
Note that the term "throat" has been avoided. Some performers refer to the "orifice" as the "throat" of the mouthpiece. There are others who consider the bottom of the cup, or the "shoulder of the throat" as the throat. Since this conflict exists, the term "orifice" is used herein for the narrowest portion of the mouthpiece which is the cylindrical portion between the backbore and the shoulder of the throat. The entire cup, including the "shoulder of the throat", will be discussed as a unit.
The parts of the mouthpiece are interacting, and bear a relationship to each other in that any one part can not be changed too much without necessitating a change in the other parts. These interrelationships actually can be shown mathematically by an acoustician. For instance, the ratio of the volume of the cup to the size of the orifice and the size of the backbore is important. This ratio was not the same in the two mouthpieces shown in Figure 1. The change in ratio caused the slight sharpening of the extreme high register. If the ratio had been the same, the entire instrument would have been flattened by the larger mouthpiece.
If a mouthpiece is constructed with a proper balance between the various components, then it generally will be rated as a "good" mouthpiece. Some player will like it, even though it might not exactly match the individual requirements of most players. On the other hand, if the interrelationship between parts is not carefully designed, then every player will immediately condemn the mouthpiece. It is easy for any musician to determine this for himself. Simply drill a 5/16" hole through the orifice of an expendable trumpet or cornet mouthpiece. No one will rate the result as a "good" mouthpiece on any instrument because the interrelationship of the component parts has been destroyed. Note that this completely changes the electrical response pattern. (Figure 5). (Note: In this and all following response graphs, the higher each peak, the more resonance on that particular note, with intonation change shown in cents sharp (+) or flat (-).)
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| FIGURE 5: EFFECT OF EXTREMELY LARGE ORIFICE Intonation is shown as the change in cents caused by large orifice. |
The intonation of the instrument has been seriously affected, with the lower tones flattened and the upper register sharpened.
The shapes of several mouthpieces are shown in Figure 6.
| FIGURE 6. VARIOUS MOUTHPIECE SHAPES A: Kryll | B: Popular Modern | C: Glantz | D: Double Cup | E: Llewellyn |
Each of these was a reasonably "good" mouthpiece in that all of the components bore a relationship to each other which made the mouthpiece respond as such. In addition, each mouthpiece matched the exact needs of some particular player. However, these mouthpieces were different enough that practically no player would like all of them, because of individual player needs.
THE THROAT (“ORIFICE”)
If the cup volume stays the same and the size of the orifice is changed, the "resistance" of the mouthpiece is also changed. The larger the orifice, the greater the demands on the physical development of the embouchure. If the orifice becomes very large, it is difficult to play a pianissimo, especially in the high register, but an overall bigger volume of tone is possible. Usually, a medium-sized orifice, matched to the rest of the mouthpiece, is desirable for producing an even response in all registers and a good intonation pattern, plus endurance. The change in resonance and intonation caused by a larger orifice is shown in Figure 7.
| FIGURE 7. EFFECT OF ENLARGED ORIFICE Intonation is shown as the change in cents caused by larger orifice. |
Note that the resonance is decreased, particularly in the upper register, and that the upper register is sharpened by the enlarged orifice.
A longer orifice increases the "resistance" to the player. The change caused by lengthening a trumpet mouthpiece orifice to nearly one inch, without changing the diameter, is shown in Figure 8.
| FIGURE 8: EFFECT OF LONG ORIFICE Intonation is shown as the change in cents caused by longer orifice. |
Note the change in resonance pattern emphasizing the middle register, with a loss of resonance on the higher notes. Also, note that the lower notes are sharpened and the upper notes flattened by the increased orifice length.
Both the length and diameter of the orifice must be matched to the other components of the mouthpiece, in order to obtain optimum performance.
BONUS: Scott Laskey's Notes about Throats
EDITOR’S NOTE: The following subsections were adapted from the notes of Scott Laskey and James F. Donaldson as obtained from EVERYTHINGTRUMPET.COM. This content was not included in the original Conn blue booklet. Refer to the larger archive of Jim Donaldson's The Schilke Loyalist and The Trumpet Gearhead content hosted here.
Enlarging the throat of a mouthpiece
For many, enlarging the throat is synonymous with "free-er blowing". While the throat is the only component in the mouthpiece which has direct control over how much air actually passes through the mouthpiece, however, other factors contribute even more to the perception of air flow. For example, rim contour controls how freely the lip vibrates. When lip vibration is less restricted, we perceive the mouthpiece to be more "free blowing". Also, mouthpiece mass also affects the perception of resistance, as both Bach, in the Megatone line, and Monette automatically increase the size of the throats of their heavyweight mouthpieces to compensate for the increased perception of resistance caused by the mass of the mouthpiece. The exterior mass of the mouthpiece cannot affect the actual quantity of air passing through the mouthpiece, but it does affect the perception of the player.
The "feel" is too often used to determine what is needed when choosing the instrument we play or the mouthpiece alterations we make. Sound is a much better judge in helping us determine the necessary changes in our equipment. While we may initially not like the feel of something, it is amazing how our perception of a "feel" changes when the sound and performance are improved.
In any event, it is clear that opening the mouthpiece throat does allow the player to put a greater volume of air through the mouthpiece. The benefits of this are:
- Less edge at louder decibels. The musician is able to play louder before the sound begins to get "edgy". Laskey believed it is for this reason that most orchestral musicians use much larger throats today. Their need to play incredibly loud without distortion is essential to their job.
- Thicker, darker core. The sound (abstractly) takes on a thicker, darker core.
- The ability to play softly is increased with the larger throat. While it is probably less efficient, it is the inefficiency that makes this so. We use more air while still playing at soft volumes, making the playing of the trumpet less treacherous in such passages.
- A larger throat could be beneficial for some students. Using a larger throat can be beneficial to a student, especially if his or her focus is on how they sound as opposed to how they feel when they play. If they focus on how they sound, the larger throat will help the student to develop the volume and the constant air flow we strive to teach. The air flow will become a natural process with little need to guide or consciously try to adjust the physical technique. Conversely, if the student cannot pick up on the difference in sound and emulate it by producing a better flow of air, playing will become more difficult and his or her sound will not be supported.
With a larger throat, however, there is a need to support the air flow to a much greater degree than with a smaller throat. If the player doesn't support the air flow sufficiently or opens the throat to a point where he or she can no longer adequately support the air flow, the player will produce a very thin and weak sound with a lack of overtones and without a focus or core to the sound. In addition, the player fatigues more quickly and range diminishes.
Intonation changes after throat enlargement
Everything in a mouthpiece affects everything in the mouthpiece. Changing rim contour affects intonation. Changing mass displacement affects intonation. Changing backbores affect intonation, and, yes, changing throat sizes affects intonation. But the specific effect of the change is relative to the backbore, throat size, throat length, inside diameter, outside diameter, cup shape, and cup volume of the mouthpiece.
Any change in intonation, however, will be as much a function of throat shape as it is throat size. A tapered throat is where the throat dimension is a single point in either a constant or dual taper; a cylindrical throat is where the throat is actually a cylinder in the mouthpiece having the same width over a certain length. Some throats are made of parts of each. Opening the throat with a drill, without adjusting for any taper in the throat, will turn a tapered throat into a cylindrical one. As a general rule, the longer the cylindrical section in the throat, the more focus or center to the sound, but the more it tends to condense or shrink the octaves, meaning the lower register goes sharp and the upper register becomes flat. As the cylinder is shortened (either from the backbore or the cup side) the octaves then augment or spread apart--all relative to the other aspects that makeup the mouthpiece.
Tonal effects of enlarging the throat vs. backbore
Enlarging the throat typically alters the tone color (usually darker) and enlarging the backbore typically alters the (again abstract term) shape of the sound.
As Scott Laskey illustrated:
- The backbore is like the hand sprinkler we put on the end of a water hose. We can control the shape of the spray and the disbursement of the water by changing the settings on the sprinkler, like we can control tonal color by altering the backbore.
- The throat of the mouthpiece is more like the size of the hose itself. A smaller diameter hose will allow a smaller amount of water to pass through it. A larger hose will allow more water to flow through. In our application, more air will flow through the larger throat which will allow more overtones to become present in our sound and give us a thicker, denser quality to our sound.
But still, the overriding factor is how much volume of air is being used and the velocity of air being used to set everything into motion.
THE BACKBORE
The backbore of a mouthpiece has a definite effect on both tone quality and intonation. If the backbore of a mouthpiece is too small, the high register will be "stuffy" and usually flat. On the other hand, if the backbore of a mouthpiece is too large, the response may not have sufficient resistance and the instrument will perform in a "loose" manner. The octaves will be stretched somewhat, with the high tones slightly sharper.
Figure 9 shows the difference in resonance between a much smaller than normal backbore and a normal-sized one, with all other factors the same. Both the resonance and intonation patterns are changed so much that the instrument is virtually unplayable.
| FIGURE 9. EFFECT OF SMALL BACKBORE Intonation is shown in cents caused by small backbore. |
MATTHEW R. FROST: Trumpet Mouthpiece Backbores: An Investigation of Interior Volume and Timbre
In Matt Frost's 2014 study of trumpet mouthpiece backbores, the author described the shape of the backbore by breaking it into "segments", as follows:
Comparing the interior volumes of each segment generally describes the rate of taper, or shape, of the backbore. [...] The shape of the backbore has a strong correlation to timbre. [...] In general:
- As the rate of taper in the middle section of a backbore increases the timbre gets darker; conversely, as the taper decreases the timbre gets brighter, in the lower and upper registers.
- When the rate of taper of the small-middle end of the backbore is increased, the timbre of the trumpet gets brighter in the middle register. When the rate of taper of the small-middle end of the backbore is decreased, the timbre of the trumpet gets darker in the middle register.
- When the rate of taper of the small end of the backbore is increased, the timbre gets brighter in the middle register. When the rate of taper of the small end of the backbore is decreased, the timbre gets darker in the middle register.
To download and read Matt Frost's study, refer to the original PDF hosted by the University of Washington here.
THE CUP VOLUME AND SHAPE
The volume of the cup is a primary determinant of tone quality, of pitch level, and of intonation. A cup with a larger volume aids in the production of a "darker", "rounder", "fuller" sound. However, the resonance pattern of the larger cup is such as to make the higher notes less responsive. In addition, the entire instrument is made flatter by the larger cup. See Figure 10.
| FIGURE 10: LARGER VS. SMALLER CUP Intonation shown as number of cents that larger cup is different from smaller one. |
Experiments using mouthpieces with exactly the same volume, same orifice diameter, same rim, but with different cup shapes indicate that cup volume is more important than cup shape, especially in respect to intonation. However, there is much subjective evidence to indicate that the shape of the bottom of the cup, or the "shoulder of the throat" does affect tone quality, and to a lesser degree, the "resistance" of the instrument. The general "rule of thumb" is that a cup shaped in as in "A", which blends smoothly into the orifice, will have less stridency of sound than will a cup with the abrupt change shown in "B of Figure 11:
| FIGURE 11. CUP SHAPES WITH DIFFERENCES IN THE "SHOULDER OF THE THROAT” |
THE CUP DIAMETER
One of the most important factors in a mouthpiece is the cup diameter. If the cup diameter is enlarged, and the same basic cup shape is retained, the volume of the cup is obviously enlarged (See Figure 12).
| FIGURE 12. EFFECT OF CUP DIAMETER ON CUP VOLUME |
Because of the increased diameter, both the length and the area of the lips inside the rim are increased. As a result, without player compensation, the lips tend to vibrate at a lower frequency and usually in a manner which emphasizes the lower partials of the sound, thus "darker". The actual effect on the lips is, of course, evident in electronic measurements as was seen in Figure 10. Even if the vibration of the lips were not affected, the resonance pattern of the larger cup would make the higher notes less responsive.
Because the larger diameter covers a greater area of the player’s lips, greater muscular control is required to play the higher register. However, usually a greater volume of tone in the low and middle registers is possible with less effort. Players who are accustomed to a large cup diameter, and have developed sufficient muscular control, are able to produce compact and uniform high, middle, and low registers with great flexibility.
THE RIM
Figure 13 shows the three basic portions of a mouthpiece rim. Most mouthpieces have a fairly sharp radius on the inner edge combined with a medium wide rim with a somewhat rounded curvature. The latter provides a surface which distributes the pressure over a large portion of the lips.
| FIGURE 13. THE MOUTHPIECE RIM |
The inner edge or "bite" is by far the most important part of the mouthpiece rim.
Marcinkiewicz Co. adds: "the bite should not be so sharp that it cuts into the flesh, but not so flat as to provide no bite. Bite is defined by the ability to hold the mouthpiece to the lips without excess pressure, and still feel comfortable." (source)
Just as one must press the finger down tightly on a stringed instrument in order to produce a clear tone, so must one also have a definite contact point for the embouchure at the inner edge of the rim. However, during performance, the embouchure is constantly changing its rate of vibration. For this reason, the exact effect of the "bite" will vary somewhat from player to player because of individual peculiarities of the embouchure and its muscular structure.
Generally speaking, a small radius on the inner portion of the rim (a sharper bite) provides more accurate attacks and greater precision. This is true because a more definite termination point is provided for the vibrating areas. When the inner edge is more rounded, attacks and intonation may not be as precise, but greater flexibility may be provided. However, this varies according to the individual embouchure, and the rim which is most comfortable and efficient for one player may not suit another.
A mouthpiece with a sharper bite often responds like a slightly smaller diameter mouthpiece. Consequently, the sharper bite will tend to provide a somewhat brighter sound, or a tone with a little more "edge", and perhaps even a very slightly higher pitch.
SUMMARY
Aside from the personal factor of varying individual needs, the most misunderstood aspect is the interrelationship of the various parts of a mouthpiece. At the risk of oversimplification, a quick guide to the effects of those components is shown in Figure 14. As has been pointed out, the reaction of each musician, and even his terminology, is dependent on background, training, and physical characteristics. Consequently, a brief listing such as this may not be true in every individual case. However, these tendencies are definite factors with which the mouthpiece designer must cope. The effects of larger dimensions are shown in the chart. The reverse effect would be true if dimensions were smaller. CAUTION: This information is not to be used as a guide for reworking mouthpieces. Any such changes destroy the designed interrelationship of the mouthpiece components, and the mouthpiece may be ruined.
NOTE: THE FIT OF THE MOUTHPIECE INTO THE INSTRUMENT IS QUITE IMPORTANT BUT IS NOT DISCUSSED HEREIN. All Conn cup mouthpieces (except Bass Trombone) have a shank designed according to the music industry standard of 0.050" per inch taper with an outer diameter at the small end of 0.339" for the cornet and 0.385" for the trumpet.
| FIGURE 14. A CONDENSED GUIDE TO THE EFFECT OF THE VARIOUS MOUTHPIECE COMPONENTS |
