Denis Wick RW3 vs Kelly 5C
The Kelly 5C has a wider cup diameter, the Denis Wick RW3 has a larger throat opening.
Cup Diameter
The Kelly 5C has a cup diameter of 16.76 mm / 0.6598 in compared to 16.75 mm / 0.6594 in on the Denis Wick RW3 — a difference of 0.01 mm / 0.0004 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 Denis Wick RW3 has a wider throat (4.57 mm / 0.1799 in vs 3.80 mm / 0.1496 in). A wider throat allows more air through, increasing volume and projection but reducing resistance.
Material
The Denis Wick RW3 is described as unspecified, and the Kelly 5C 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.