Kelly 24AW vs Kelly X-SMALL
The Kelly 24AW has a wider cup diameter, the Kelly 24AW features a deeper cup.
Mouthpiece A
Kelly 24AW
• Tuba
GeneralCup diameter31.24 mm / 1.2299 in
Cup depthVery deep
Rim width—
Throat diameter—
BackboreXL
Finish—
MaterialLexan polycarbonate
Best suited for
Orchestral playing — large cup for full, dark tone
Tuba / sousaphone
vs
Mouthpiece B
Kelly X-SMALL
• Tuba
StudentCup diameter30.73 mm / 1.2098 in
Cup depthShallow
Rim width—
Throat diameter—
BackboreS
Finish—
MaterialLexan polycarbonate
Best suited for
Student / Eb tuba / euphonium doubler
Cup Diameter
The Kelly 24AW has a cup diameter of 31.24 mm / 1.2299 in compared to 30.73 mm / 1.2098 in on the Kelly X-SMALL — a difference of 0.51 mm / 0.0201 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
The Kelly 24AW has a very deep cup while the Kelly X-SMALL has a shallow cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.
Material
Both mouthpieces share the same listed material (Lexan polycarbonate).
Which is better?
The Kelly 24AW is designed for general playing, while the Kelly X-SMALL targets student use. Your best choice depends on your musical context.