Bach 5V vs Yamaha CR-11E4S
The Yamaha CR-11E4S has a wider cup diameter, the Yamaha CR-11E4S has a larger throat opening.
The internal diameter of the cup, measured at the widest point inside the rim.
Mouthpiece A
Bach 5V
• Cornet
Cup diameter16.25 mm / 0.6398 in
Best suited for
High-volume projection — open throat for power
vs
Mouthpiece B
Yamaha CR-11E4S
• Cornet
Cup diameter16.46 mm / 0.6480 in
Best suited for
High-volume projection — open throat for power
Cup Diameter
The Yamaha CR-11E4S has a cup diameter of 16.46 mm / 0.6480 in compared to 16.25 mm / 0.6398 in on the Bach 5V — a difference of 0.21 mm / 0.0083 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.