The different types of trombone mouthpieces can be classified according to whether they are suitable for a beginner, an intermediate player, or an advanced player. These classifications depend on the various aspects of the mouthpiece, such as its rim, its cup, and its throat. Most comparison charts for trombone mouthpieces focus solely on the cup diameter. A larger cup is better for more advanced players who have more control over their embouchure. Other factors, such as the depth of the cup and the sharpness and thickness of the rim can also affect the mouthpiece.
Most trombone mouthpieces are differentiated by the diameter of the cup. The cup is the main section of the mouthpiece, which the player blows into. A large cup — up to 1.142 inches (29 millimeters) — provides players with more control and increased volume, but it can be difficult to use for beginners. A smaller cup — as small as 0.886 inches (22.5 millimeters) — will help players produce an even tone and make the instrument easier to play. Choices somewhere between these two extremes are more suitable for intermediate players.
The depth of the cup can affect the tones produced on trombone mouthpieces. A deep cup is suitable for players looking for a darker or warmer tone, particularly on notes in the lower register. The opposite, a shallow cup, is effective for players wanting to produce a brighter or more biting tone. A shallow cup also improves the response of the mouthpiece, which is important for some more advanced players.
The rim is another important aspect for players to consider when buying new trombone mouthpieces. Beginners are more suited to wide rims with rounded edges. The rim is the circular opening on the mouthpiece with which the player’s mouth comes into contact. Choosing a wide rim allows players more endurance when playing, and a rounded edge gives beginners increased comfort. More advanced players should choose a narrow and sharpened rim for better tonal range and precision of attack.
Each mouthpiece has a small section underneath the cup called the throat. The size of the throat on trombone mouthpieces can affect the intonation of the instrument. Generally speaking, a larger throat gives advanced players more freedom for tone and volume production, and is therefore preferable. Smaller throats are therefore considered better for beginners, because they don’t require as strong an embouchure. The high register is flattened by small throats and sharpened by large ones.