Curry 1.25 DC vs Kelly 3C
The Curry 1.25 DC has a wider cup diameter, the Kelly 3C has a larger throat opening.
Cup Diameter
The Curry 1.25 DC has a cup diameter of 17.07 mm / 0.6720 in compared to 17.02 mm / 0.6701 in on the Kelly 3C — a difference of 0.05 mm / 0.0019 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
Both mouthpieces share a very deep cup depth, so the sound character from depth alone will be very similar.
Throat Diameter
The Kelly 3C has a wider throat (4.06 mm / 0.1598 in vs 3.81 mm / 0.1500 in). A wider throat allows more air through, increasing volume and projection but reducing resistance.
Material
The Curry 1.25 DC 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.