Bach 5V vs Yamaha CR-8D2S
The Yamaha CR-8D2S has a wider cup diameter, the Bach 5V features a deeper cup.
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-8D2S
• Cornet
Cup diameter16.36 mm / 0.6441 in
Best suited for
High-volume projection — open throat for power
Cup Diameter
The Yamaha CR-8D2S has a cup diameter of 16.36 mm / 0.6441 in compared to 16.25 mm / 0.6398 in on the Bach 5V — a difference of 0.11 mm / 0.0043 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.