Kelly 24AW vs Kelly 25
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 25
• Tuba
GeneralCup diameter30.99 mm / 1.2201 in
Cup depthMedium
Rim width—
Throat diameter—
BackboreM
Finish—
MaterialLexan polycarbonate
Best suited for
General tuba / euphonium doubler
Cup Diameter
The Kelly 24AW has a cup diameter of 31.24 mm / 1.2299 in compared to 30.99 mm / 1.2201 in on the Kelly 25 — a difference of 0.25 mm / 0.0098 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 25 has a medium 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?
Both mouthpieces are categorized as "General" — the physical dimensions above will determine which suits your embouchure and playing style better.