Which has a bigger cup — Bach 12 or Bach 12B?

Both mouthpieces have virtually identical cup diameters at 15.20 mm / 0.5984 in.

How does cup depth compare between Bach 12 and Bach 12B?

The Bach 12 has a very deep cup while the Bach 12B has a deep cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.

Bach 12 vs Bach 12B

Name: Bach 12B
Brand: Bach

the Bach 12 features a deeper cup.

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 12

• Cornet

Rim width—

Mouthpiece B

Bach 12B

• 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.