Bach 1½C vs Kelly 5C
The Bach 1½C has a wider cup diameter, the Kelly 5C features a deeper cup, the Kelly 5C has a larger throat opening.
The narrowest point at the bottom of the cup. Affects resistance, volume, and tone color.
Mouthpiece A
Bach 1½C
• Cornet
Throat diameter3.66 mm / 0.1441 in
vs
Mouthpiece B
Kelly 5C
• Cornet
GeneralThroat diameter3.80 mm / 0.1496 in
Best suited for
High-volume projection — open throat for power
Mid-range all-purpose
Throat Diameter
The Kelly 5C has a wider throat (3.80 mm / 0.1496 in vs 3.66 mm / 0.1441 in). A wider throat allows more air through, increasing volume and projection but reducing resistance.
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.