Curry 3 C. vs Kelly 3C
The Kelly 3C has a wider cup diameter, the Kelly 3C features a deeper cup, the Kelly 3C has a larger throat opening.
Cup Diameter
The Kelly 3C has a cup diameter of 17.02 mm / 0.6701 in compared to 16.89 mm / 0.6650 in on the Curry 3 C. — a difference of 0.13 mm / 0.0051 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
The Kelly 3C has a very deep cup while the Curry 3 C. has a medium cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.
Throat Diameter
The Kelly 3C has a wider throat (4.06 mm / 0.1598 in vs 3.70 mm / 0.1455 in). A wider throat allows more air through, increasing volume and projection but reducing resistance.
Material
The Curry 3 C. is described as unspecified, and the Kelly 3C as Lexan polycarbonate. Material affects mass, warmth, and how quickly the piece responds.
Which is better?
Neither mouthpiece clearly dominates the other — the right choice depends on your embouchure, playing style, and the sound you're after. Try both if possible.