Bach 7C vs Kelly SHEW-JAZZ
The Kelly SHEW-JAZZ has a wider cup diameter, the Kelly SHEW-JAZZ features a deeper cup, the Kelly SHEW-JAZZ has a larger throat opening.
Cup Diameter
The Kelly SHEW-JAZZ has a cup diameter of 16.51 mm compared to 16.20 mm on the Bach 7C — a difference of +0.31 mm. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
The Kelly SHEW-JAZZ has a — cup while the Bach 7C has a medium cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.
Throat Diameter
The Kelly SHEW-JAZZ has a wider throat (4.06 mm vs 3.66 mm). A wider throat allows more air through, increasing volume and projection but reducing resistance.
Material
The Bach 7C is described as unspecified, and the Kelly SHEW-JAZZ 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.