Denis Wick 2.5CC vs Kelly X-SMALL
The Denis Wick 2.5CC has a wider cup diameter, the Denis Wick 2.5CC features a deeper cup.
Cup Diameter
The Denis Wick 2.5CC has a cup diameter of 32.00 mm / 1.2598 in compared to 30.73 mm / 1.2098 in on the Kelly X-SMALL — a difference of 1.27 mm / 0.0500 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
The Denis Wick 2.5CC has a 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
The Denis Wick 2.5CC is described as unspecified, and the Kelly X-SMALL 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.