Which has a bigger cup — Bach 12 or Bach 17C?

The Bach 12 has a cup diameter of 15.20 mm / 0.5984 in compared to 15.10 mm / 0.5945 in on the Bach 17C — a difference of 0.10 mm / 0.0039 in. A wider cup generally produces a fuller, darker tone but requires more air support.

Bach 12 vs Bach 17C

Name: Bach 17C
Brand: Bach

The Bach 12 has a wider cup diameter, the Bach 12 features a deeper cup.

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

How deep the cup is, from shallow (brighter, easier high register) to deep (darker, fuller sound).

Mouthpiece A

Bach 12

• Cornet

Cup depthVery deep

Mouthpiece B

Bach 17C

• Cornet

Cup depthMedium

Cup Depth

The Bach 12 has a very deep cup while the Bach 17C has a medium cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.

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.