Which has a bigger cup — Bach 11½A or Bach 12?

The Bach 11½A has a cup diameter of 15.65 mm / 0.6161 in compared to 15.20 mm / 0.5984 in on the Bach 12 — a difference of 0.45 mm / 0.0177 in. A wider cup generally produces a fuller, darker tone but requires more air support.

How does cup depth compare between Bach 11½A and Bach 12?

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

Bach 11½A vs Bach 12

Name: Bach 12
Brand: Bach

The Bach 11½A has a wider cup diameter.

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

The taper behind the throat leading to the shank. Affects projection and tone character.

Mouthpiece A

Bach 11½A

• Cornet

Backbore—

Mouthpiece B

Bach 12

• Cornet

Backbore—

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.