Which has a bigger cup — Bach 10B or Bach 9B?

The Bach 9B has a cup diameter of 16.05 mm / 0.6319 in compared to 16.00 mm / 0.6299 in on the Bach 10B — a difference of 0.05 mm / 0.0020 in. A wider cup generally produces a fuller, darker tone but requires more air support.

How does cup depth compare between Bach 10B and Bach 9B?

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

Bach 10B vs Bach 9B

Name: Bach 9B
Brand: Bach

The Bach 9B has a wider cup diameter.

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

The narrowest point at the bottom of the cup. Affects resistance, volume, and tone color.

Mouthpiece A

Bach 10B

• Cornet

Throat diameter3.66 mm / 0.1441 in

Mouthpiece B

Bach 9B

• Cornet

Throat diameter3.66 mm / 0.1441 in

Throat Diameter

Throat diameters are essentially identical at 3.66 mm / 0.1441 in, so resistance feel will be comparable.

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.