Bach 8½A vs Kelly 4B-UK
The Kelly 4B-UK has a wider cup diameter, the Kelly 4B-UK features a deeper cup, the Kelly 4B-UK has a larger throat opening.
The narrowest point at the bottom of the cup. Affects resistance, volume, and tone color.
Mouthpiece A
Bach 8½A
• Cornet
Throat diameter3.66 mm / 0.1441 in
vs
Mouthpiece B
Kelly 4B-UK
• Cornet
OrchestralThroat diameter4.37 mm / 0.1720 in
Best suited for
High-volume projection — open throat for power
Professional cornet; British brass band
Throat Diameter
The Kelly 4B-UK has a wider throat (4.37 mm / 0.1720 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.