• Design Factors in Euphonium Mouthpieces

    Mouthpiece Design

    originally written by Tranquillo Forza
    summarized for this site by Silvano Franzi

    I have observed that several euphoniumists do not have a precise knowledge of how a mouthpiece is made and how it can influence the sound we get from our instrument. This is due, in part, to the scarce or almost non-existent literature on the subject. To remedy this, I would like to point out an interesting work written by one of my compatriots twenty years ago which examines the various aspects of the mouthpiece and provides an exhaustive picture of the subject in all aspects. I purchased this book in 2002, from which I learned everything there was to know about mouthpieces and which allowed me, over the years, to successfully modify some MPs whose features didnít satisfy me. For those wishing to learn more about the subject: "Il bocchino nei labiofoni", Editions Bim. In this book, the author has presented an exhaustive analysis of the mouthpiece, its component part, their function, and how different mouthpieces work. After reading this book, the curious reader should have no more questions! The information is all here. For those not familiar with Italian I write a brief summary of the first part below. For others parts I only give a description of the topics covered.

    Premise: in order to avoid misunderstanding or false hopes we clarify here that there are no mouthpieces specifically for the high range or low range, but rather models that can help in all registers provided that the musician is already able to obtain these notes; this is achieved only with a study of the challenging and constant technique. All the descriptions that follow are necessarily brief and serve only to give a rough indication of the functioning and characteristic of the various parts making up the mouthpiece. Those interested in learning more about the subject can find in the book very useful information by consulting the comparative tables of different brands.

    Mr. Franzi will summarize the first few chapters...

    The components of the mouthpiece are:
    • EDGE, (Rim) formed by:
      • External edge, Profile (Rim shape)
      • Inner edge (connection between the end of the edge and the beginning of the cup (Bite)
      • Thickness
      • Internal diameter (internal diameter of the rim).

    • CUP, consisting of: Profile, Knee curve, Volume.
    • SHANK, formed by: Throat, Backbore and External side.
    • ADDITIONAL PARTS: Booster, BERP, Adapter Variator of impedance.


    It is the main point of contact between the musician and his instrument, and it is of fundamental importance for comfort and safety in execution. The thickness of the rim determines the width of the surface of contact between the edge and the lips. When evaluating the thickness of the edge, comfort is the most important factor to be taken into consideration. However, other factors such as agility and resistance they must be taken into consideration because, for example, a MP that at first sight is comfortable on the lips can subsequently be disastrous for the mouth. The choice of the rim depends on the physiology of the player - a wide rim favors subjects with thin lips as the pressure exerted on the mouthpiece is distributed over a wider surface improving resistance, while people with full lips benefit from greater freedom of movement and improve the sound by adopting a narrow border. In short, a narrow rim allows for greater agility, while a broad rim has greater resistance.

    So the use of a rim that is too wide leads to:
    1. insufficient tone production
    2. difficult separation
    3. lack of agility

    A rim that is too narrow leads to:
    1. lack of resistance
    2. lip cutting (cooking cutter syndrome, in extreme cases of high lip pressure.)

    In summary, it is advantageous to choose a rim that is comfortable and that also allows strength and flexibility.

    The inner diameter of the rim is the maximum distance existing between the two internal points of the rim positioned on the inner edge and is one of the fundamental elements for adapting the lips to the edge and must be carefully evaluated during the mouthpiece selection. By adopting an inadequate diameter (the adequacy of the measurement of the inner diameter is always relative to the morphological characteristics of the lips and to degree of technical development of the performer) it is possible to considerably weaken the embouchure and limits its possibilities of development of the executive technique.

    In general, when the internal diameter is too small, the following problems occur:

    1. Lack or weakness of the low register. The inner diameter determines the maximum distance between the two last points of contact between the lips and the mouthpiece, thus limiting the freedom of vibration of the lips; that is, it circumscribes the possibility of vibration of the lips around a range of frequencies. If this diameter is too narrow, the part of the lips that can freely vibrate is not sufficient for an optimal production of the low register which is notoriously associated with slow vibrations, which typically require large and flexible vibrating surfaces.
    2. Poor sound quality. It is due to the fact that the lips do not have enough space to vibrate freely, thus generating a harsh and dry sound, opposite to a fluid and homogeneous sound.

    When, on the other hand, the internal diameter is too large, we will encounter the following problems:

    1. Lack or weakness in the high register. The larger the surface of the lips, the greater the strength and time required to develop and maintain the high register. A too large internal diameter causes unless tension that lead to a waste of the available physical potential.
    2. Lack of resistance. A musician who plays with a too large internal diameter is forced to constantly supply the maximum energy to maintain his mouthpiece and is therefore forced to rest earlier and more often than those who are properly equipped.
    3. Unstable intonation.
    4. Dull and muffled sound. A large diameter makes it more difficult to produce the upper harmonic components of the sound, thus removing the timbreís brilliance.
    5. Lack of fluency. With a too large diameter the lips are generally too stretched or too open to make fast and clean ligatures and jumps.

    Summarizing: It is advantageous to choose a border that is comfortable and offers strength and flexibility. The wider the inner diameter the easier it is produce the low notes, while the smaller the inner diameter the easier it is to obtain the high notes (if these are already the musicianís heritage!). A border with a large thickness provides greater strength, but decreases flexibility and tends to produce a dull sound. A small rim gives more flexibility and precision bur requires a lot resistance especially if you have a tendency to use high pressure. A convex border profile allows greater flexibility, but decreases resistance, while a flat edge profile generates a feeling of greater safety, but tends to make the chops assume a static position and reduces flexibility. A well-rounded border helps to achieve homogeneous bonding, but it not effective for good attacks, but it makes jumps abrupt and difficult to control. A wide border allows more resistance to thin lips, while a narrower one offers greater agility to full lips.

    The habits of the individual must be kept in mind, such as the degree of pressure, the degree of technical preparation, the kind of music practiced, etc.


    The cup with a C-shaped profile compared to the V-shaped cup has greater air flow resistance and greater turbulence between the cup and throat. In addition, the C-cup brings out the higher-order harmonics, while the V-cup brings out the fundamental component of the sound.

    Clarification: to understand the role of the C or V configuration of the cup profile in sound production, it is useful to remember that a fundamental difference between the cylindrical and conical developing instruments is the greater and the lower accentuation of the bell. The purpose of the bell is to reflect the sound wave and the more the flaring of the bell is accentuated, as in the trumpet, the greater the part of reflected energy. This reflection leads to the formation of stationary waves that can assume a very high intensity. Moreover, the higher the frequency, the less it is reflected by the bell. Here then is that the bell acts as a high pass filter, i.e. it tends to favor the escape of high frequency components. It is common ground that a note generated by a brass player is formed by the fundamental note plus the higher order harmonics; here then that, depending on the type of bell, a sound with greater or lesser components of the fundamental frequency is obtained. For example, the horn or euphonium, which are instruments with conical development, form stationary waves with minor harmonics with respect to the bell of a trumpet or trombone, causing a dark color of the sound. On the other hand, a trumpet and instruments with a prevalence of cylindrical development tend to transform a higher frequency spectrum into stationary high-pressure waves, producing a brilliant sound. The shape of the mouthpiece is therefore very important: in fact, in a flugelhorn or in an euphonium where lower intensity stationary waves are formed, a greater flow of air is necessary to maintain a given oscillation. Here then is that an V-shaped cup mouthpiece will be preferable to one with a C-shaped cup. In a trumpet where there are higher intensity stationary waves, a C- shaped cup mouthpiece is preferable to help maintain the necessary pressure.


    1. The choice of the cup must be made in such a way as to satisfy the subjective needs of the musician, remembering that it goes to affect, within certain limits, the sound qualities.
    2. The profile internal of the cup influences the timbre and ease in obtaining the low or higher register. The cup with a C-shaped profile, compared to the V-shaped cup, has a greater resistance to air flow and greater turbulence in the passage of air between the cup and the groove. Furthermore, the C-cup brings out the higher-order harmonics, while the V-cup brings out the fundamental component of the sound.
    3. The profile of the cup assumes a fundamental importance in accentuating or balancing the characteristics of the individual instruments (see up "clarification").
    4. The profile of the cup can also support the performer in the use of his instrument, such as, for example, in conical instruments, that require an air flow of greater intensity to maintain a given oscillation: combining a mouthpiece with a V-shaped cup allows this intensity to be easily obtained and therefore facilitates the maintenance of intonation.
    5. The volume, through the diameter, the profile and the depth, affects the sound intensity; in particular, to a greater volume of the cup correspond richer and wider sounds.
    6. A deep cup favors a dark sound and low register, while a shallow cup favors a clear sound and the execution of high register.
    7. A large diameter cup allows a greater portion of the lips to vibrate in the mouthpiece and thus results in a wider sound. Large cups are therefore adequate to obtain a rich timbre, as long as the mouth is sufficiently developed.
    8. The labial morphology of the musician can constrain the choice of the cup. For example, the (trumpet) player with fleshy lips, may encounter greater difficulties in using a mouthpiece with a shallow cup to get the low register, due to the physical contact with the bottom of the cup.


    The shank consists of the THROAT and the BACKBORE.

    The THROAT is the part of the mouthpiece that has the smallest diameter and has the function of measuring the resistance caused by the passage of air. Acting on them can therefore facilitate the achievement of the right balance between the level of air pressure that the musician blow into the instrument and the degree of resistance, and therefore of back pressure, that he opposes. Then the throat acts as a regulator for the level of air pressure inside the cup. The size of the throat therefore determines the adequacy of the mouthpiece to the respiratory capacity of the musician. Therefore, a throat with a large diameter produces a sound of greater volume, while a throat with a small diameter tends to produce a smaller sound volume. If the diameter is too large the sound becomes unstable, while if it is too small the sound dynamics is affected.

    The BACKBORE is the part of the mouthpiece that extends downstream from the throat. It can be analyzed under two aspects: one of an acoustic nature and one of a fluid-dynamics nature. The first one, related to the shape, affects the tonal quality, while the second one, which can be described as the difference between the throat diameter and the diameter of the bore, allows to connect sections of different diameters with the minimum penalization of the continuity of the flow of air. It is desired, therefore, to connect the two parts in the best possible way, minimizing the turbulence in the air flow that would add spurious components to the sound.

    A narrow backbore tends to make
    1. A brighter sound
    2. An increase in air flow resistance
    3. Good support in the execution of the high register.

    On the other hand, a wide backbore produces
    1. Greater sound volume
    2. Less resistance and greater ease in the production of the low register.

    Moreover, it assumes a significant importance in the intonation of the instrument and, although to a lesser extent than the throat, on resistance. The mouthpiece must be intact, without dents and must be cleaned regularly, and dirt deposited in the throat or in the backbore can be alter the intonation.


    This mentions "accessories" that can be added to an existing mouthpiece setup.
    1. The BERP has the function of highlighting the correctness of the vibration of the lips.
    2. The BOOSTER serves to increase the mass of the mouthpiece thus increasing the sound volume obtainable without distortion.
    3. The impedance regulator has the function of adapting the instrument to the player depending on the place of execution.
    4. Additionally, the Adapter (a shank insert, a short tube inserted between mouthpiece and mouthpipe) is used to adapt the shank of narrow pipe mouthpieces to instruments with wide pipe.

    OTHERS TOPICS to be found in the book include:


    The anatomical features of the facial muscles and chewers; dental and jaw complex conformation; respiratory system; the position of the lips with respect to the mouthpiece; the pressure of the mouthpiece on the lips; the search for the correct positioning; the adaptation of the mouthpiece to maxillofacial irregularities; labial features and mouthpiece shape; respiratory capacity and mouthpiece resistance; musical experience, anatomical features and mouthpiece.


    The baroque mouthpiece; the romantic mouthpiece; example tables


    Comparison between C and V mouthpieces on C3 and C4 with modern and baroque trumpets and mouthpieces without and with booster.

    FEATURES and TABLES for mouthpieces:
    1. BACH
    2. SCHILKE
    4. YAMAHA

    The book may be obtained from the Editions BIM site at this link:


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