Kelly 4B-UK vs Kelly 5C
The Kelly 5C has a wider cup diameter, the Kelly 4B-UK features a deeper cup, the Kelly 4B-UK has a larger throat opening.
How deep the cup is, from shallow (brighter, easier high register) to deep (darker, fuller sound).
Mouthpiece A
Kelly 4B-UK
• Cornet
OrchestralCup depth
Best suited for
High-volume projection — open throat for power
Professional cornet; British brass band
vs
Mouthpiece B
Kelly 5C
• Cornet
GeneralCup depthVery deep
Best suited for
High-volume projection — open throat for power
Mid-range all-purpose
Cup Depth
The Kelly 4B-UK has a — cup while the Kelly 5C has a very deep cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.
Which is better?
The Kelly 4B-UK is designed for orchestral playing, while the Kelly 5C targets general use. Your best choice depends on your musical context.