Conn Precision 3 vs Kelly 7C
The Kelly 7C has a wider cup diameter.
How deep the cup is, from shallow (brighter, easier high register) to deep (darker, fuller sound).
Mouthpiece A
Conn Precision 3
• Cornet
GeneralCup depthMedium
Best suited for
All-round versatile — balanced cup for general playing
All-around use; most popular model
Bright quality of tone in all registers; good all-around
vs
Mouthpiece B
Kelly 7C
• Cornet
GeneralCup depthMedium
Best suited for
All-round versatile — balanced cup for general playing
Beginner / intermediate
Cup Depth
Both mouthpieces share a medium cup depth, so the sound character from depth alone will be very similar.
Which is better?
Both mouthpieces are categorized as "General" — the physical dimensions above will determine which suits your embouchure and playing style better.