Bach 2½C vs Bach 5A
The Bach 2½C has a wider cup diameter, the Bach 5A features a deeper cup.
The width of the rim surface that contacts the lips. Wider rims improve endurance; narrower rims improve flexibility.
Mouthpiece A
Bach 2½C
• Cornet
Rim width—
Best suited for
All-round versatile — balanced cup for general playing
vs
Mouthpiece B
Bach 5A
• Cornet
Rim width—
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.