Bach 2 vs Bach 3
The Bach 2 has a wider cup diameter.
The internal diameter of the cup, measured at the widest point inside the rim.
Mouthpiece A
Bach 2
• Cornet
Cup diameter16.50 mm / 0.6496 in
vs
Mouthpiece B
Bach 3
• Cornet
Cup diameter16.30 mm / 0.6417 in
Cup Diameter
The Bach 2 has a cup diameter of 16.50 mm / 0.6496 in compared to 16.30 mm / 0.6417 in on the Bach 3 — a difference of 0.20 mm / 0.0079 in. A wider cup generally produces a fuller, darker tone but requires more air support.
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.