Bach 1B vs Kelly 4B-UK
The Bach 1B 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
Bach 1B
• Cornet
Cup depthDeep
Best suited for
Orchestral playing — large cup for full, dark tone
vs
Mouthpiece B
Kelly 4B-UK
• Cornet
OrchestralCup depth
Best suited for
High-volume projection — open throat for power
Professional cornet; British brass band
Cup Depth
The Kelly 4B-UK has a — cup while the Bach 1B has a deep cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.
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.