Dimensional Characteristics of the Trumpet Mouthpieces

By Dr. Maury Deutsch
(reprinted and edited from the September 1979 Getzen Gazette)

There is nothing more crucial for a successful trumpet or cornet career than a proper fitting mouthpiece. This clearly points out the importance of a qualified instructor for the beginning student. A pitfall that faces many young trumpeters is an orgy of mouthpiece changes. This is frequently the result of an unwarranted belief that qualities such as range, tone, endurance, flexibility, etc… can be magically improved by a mouthpiece change. This articles aims to clarify the functions and interactions of the dimensional mouthpiece characteristics and is not intended to encourage a self-induced mouthpiece change. Basic criteria for judging the efficiency of a mouthpiece are: 1) The tone possible in the lower register, 2) The ease of playing in the legitimate upper register, and 3) The lip flexibility obtainable in the middle register.

Mouthpiece Diagram

Cup Diameter (1)

The component most frequently mentioned when seeking a new mouthpiece is cup diameter. A large cup diameter favors both amplitude (tonal volume) and lower register play. The resulting tone has a mellow quality because the energy principally resides in the fundamental and lower to middle partials. With a medium cup diameter, the air pressure forces more of the energy into the upper partials with a corresponding increase of brilliance. A small cup diameter favors the highest partials. The tone then acquires an almost metallic quality.

Cup Depth (2)

Playing in the lower and middle registers is easier with a deep cup. The deep cupped mouthpiece, with its more mellow tone and greater volume, is frequently recommended for playing hymns. A shallow cup provides a greater rebound of vibratory energy. This energy return interacts with the lip vibrations resulting in an increase of vibratory intensity. High notes of metallic quality are consistent with a very shallow cup. A popular innovation used by many jazz artists is the double cup mouthpiece, i.e. a shallow cup progressing into a deeper cup. The shallow portion subtly aids the upper register and the deeper segment helps volume. A negative consequence of this is the loss of acoustical energy due to the greater number of reflective surfaces. Higher pitched trumpets (relative to the standard Bb trumpet) naturally require a narrower diameter and a shallower cup for maximum playing efficiency. On the contrary, lower pitched trumpets require both a wider diameter and a deeper cup.

Outer Rim (3)

The outer rim cushions the instrument’s impact on the lips and teeth. A narrow rim will subtly increase lip flexibility (less of the lip is demobilized). However, there is the danger of lip irritation from impact over a relatively narrow area. A wider outer rim (cushion rim) acts to aid the play of the upper register by increasing the overall lip tension. However, the vice like effect of the broad rim is a detriment to flexibility.

Inner Rim Edge (4)

The principal function of the inner rim edge is to provide termination points for vibrating lips. This is analogous to the opposite terminal points of a vibrating string. A moderately sharp inner rim makes for greater playing precision and accuracy of attacks. Too sharp an edge can cause lip discomfort and also interferes with lip flexibility. Too rounded of an inner edge has a negative influence on clean attacks and accurate intonation. However, greater flexibility is possible.

Throat (5)

Although a large throat favors a greater volume of tone, there is difficulty in playing pianissimo, especially in the upper register. The greater air pressure required to play the upper register frequently causes these tones to be slightly sharp. A narrow throat opening makes the high notes easier, but can weaken the lower register. The backwash of vibrations interacting with lip tension results in a nasal quality at lower dynamics and a metallic quality at louder dynamics. Some trumpet players extend the throat opening (without increasing the diameter) in order to obtain still greater resistance. The upper register is made easier, but there are negative consequences. The overcompensation required of the embouchure makes low notes slightly sharp and high notes slightly flat.

Backbore (6)

The back bore is encased within the shank. Too small a backbore does not permit sufficient energy to reside in the fundamentals. The result is a nasal quality as energy falls in the middle partials. In addition, the upper register has a tendency to be flat. Too large a backbore makes playing precision more difficult. Also, the upper register has a tendency to be sharp.

Remember that the ideal mouthpiece for you cannot be determined without playing it. The choice must be based on your lip, mouth, teeth, and facial characteristics. A cardinal rule is to avoid extremes in each of the constituent parts of a mouthpiece. One must choose a mouthpiece that not only meets the specific needs of the player at the time, but one that also provides the versatility to meet future needs. It is important for us all to realize that choosing a mouthpiece is more of an art than a science.

As an aside, not all mouthpieces are made of metal. Louis Armstrong carved a mouthpiece out of wood when he was a youth. Plastic mouthpieces have some advantages. The softer plastic material has a subtle positive effect on flexibility. However, intonation and clarity of attack is slightly inferior due to the lack of the firmer support from a metal mouthpiece. The greatest advantage of a plastic mouthpiece is the added comfort they provide when performing outdoors during cold weather.