Which has a bigger cup — Bach 10½C or Bach 9C?

The Bach 9C has a cup diameter of 16.05 mm / 0.6319 in compared to 15.90 mm / 0.6260 in on the Bach 10½C — a difference of 0.15 mm / 0.0059 in. A wider cup generally produces a fuller, darker tone but requires more air support.

How does cup depth compare between Bach 10½C and Bach 9C?

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

Bach 10½C vs Bach 9C

Name: Bach 9C
Brand: Bach

The Bach 9C has a wider cup diameter.

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

Base metal or construction (e.g. brass, stainless steel, plastic). Influences weight, response, and tone color.

Mouthpiece A

Bach 10½C

• Cornet

Material—

Mouthpiece B

Bach 9C

• Cornet

Material—

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.