Giardinelli 4M vs Kelly SYMPHONY-LS-SS
The Kelly SYMPHONY-LS-SS has a wider cup diameter, the Kelly SYMPHONY-LS-SS features a deeper cup.
Cup Diameter
The Kelly SYMPHONY-LS-SS has a cup diameter of 25.65 mm / 1.0098 in compared to 25.40 mm / 1.0000 in on the Giardinelli 4M — a difference of 0.25 mm / 0.0098 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
The Kelly SYMPHONY-LS-SS has a — cup while the Giardinelli 4M has a medium cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.
Material
The Giardinelli 4M is described as unspecified, and the Kelly SYMPHONY-LS-SS as 316 Surgical Stainless Steel. 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.