Bach 22 vs Yamaha BB-67C4
The Yamaha BB-67C4 has a wider cup diameter, the Bach 22 has a larger throat opening.
The internal diameter of the cup, measured at the widest point inside the rim.
Mouthpiece A
Bach 22
• Tuba
Cup diameter31.60 mm / 1.2441 in
Best suited for
High-volume projection — open throat for power
vs
Mouthpiece B
Yamaha BB-67C4
• Tuba
Cup diameter32.06 mm / 1.2622 in
Best suited for
High-volume projection — open throat for power
Cup Diameter
The Yamaha BB-67C4 has a cup diameter of 32.06 mm / 1.2622 in compared to 31.60 mm / 1.2441 in on the Bach 22 — a difference of 0.46 mm / 0.0181 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.