Choosing the best euphonium mouthpieces requires knowledge of how different factors such as rim size, cup depth and throat affect the tone produced by the mouthpiece. Other factors that can influence the sound produced include the width of the cup, the backbore and the edge of the rim. Each player may prefer a different mouthpiece, depending on the sort of tone that he or she is looking for. Learning how different aspects of a mouthpiece will affect the tone is the best way to choose a particular type.
Brass instruments rely on mouthpieces to translate the player’s lip vibrations into sound that goes down the length of the instrument. The key parts of euphonium mouthpieces, and most other brass mouthpieces, are the rim, cup, throat and backbore. The rim is the circular section surrounding the opening, which the player’s lips come into contact with. Inside the rim is the cup, which is supported by a thin tube, called the throat, which connects to it like a stem to a wine glass. The final section, further down the tube, is called the backbore.
Different rims can make different euphonium mouthpieces more or less comfortable to play, and the type of edge can affect the precision of attack for the player. A wide rim makes the instrument more comfortable to play, but doesn’t provide as much flexibility of range as a narrower rim. Beginners may prefer a wider rim, but as players get more experienced, they may want to get a narrower rim to benefit from the increased range. A sharper edge on the rim gives players more control over the tone produced, but a rounded edge is much more comfortable to play. A standard rim size is around 1 inch (25.4 millimeters).
The cup size can affect the quality of the tone produced by euphonium mouthpieces. The two key aspects to the cup of the instrument are the depth of the cup and the overall size. Deeper cups give the instrument a deeper tone and accentuate the darker, warm tones. Shallow cups do the opposite, brightening the tone and improving the instrument’s response. Larger cups provide better volume and more control, but beginners may be more suited to small cups because they are easier to play.
Large throat sizes give the player more control over the volume and tone produced by the instrument. Euphonium mouthpieces can either have small or large throats, and as is common in brass mouthpieces, the smaller ones are easier to play, but the larger ones provide a better sound. Large throats sharpen the high end of the register, and small throats flatten it. A bigger backbore can give the instrument a better depth of sound, and a smaller one allows the tone to be focused more easily.