Giardinelli Sym. T vs Kelly 12C
The Giardinelli Sym. T has a wider cup diameter, the Giardinelli Sym. T features a deeper cup.
Cup Diameter
The Giardinelli Sym. T has a cup diameter of 25.80 mm / 1.0157 in compared to 24.13 mm / 0.9500 in on the Kelly 12C — a difference of 1.67 mm / 0.0657 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
The Giardinelli Sym. T has a deep cup while the Kelly 12C has a shallow cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.
Material
The Giardinelli Sym. T is described as unspecified, and the Kelly 12C 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.