Which has a bigger cup — Bach 12C or Bach 2½C?

The Bach 2½C has a cup diameter of 16.40 mm / 0.6457 in compared to 15.20 mm / 0.5984 in on the Bach 12C — a difference of 1.20 mm / 0.0472 in. A wider cup generally produces a fuller, darker tone but requires more air support.

How does cup depth compare between Bach 12C and Bach 2½C?

Both mouthpieces share a medium cup depth, so the sound character from depth alone will be very similar.

Bach 12C vs Bach 2½C

Name: Bach 2½C
Brand: Bach

The Bach 2½C has a wider cup diameter.

Overall Comparison Cup Diameter Cup Depth Rim Width Throat Diameter Backbore Finish Material

The width of the rim surface that contacts the lips. Wider rims improve endurance; narrower rims improve flexibility.

Mouthpiece A

Bach 12C

• Cornet

Rim width—

Mouthpiece B

Bach 2½C

• Cornet

Rim width—

Best suited for

🎵All-round versatile — balanced cup for general playing

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.