Detail 01
Size 64
Bach 25 dimensions with a smaller rim diameter, so the lip contact patch is narrower.

Independent shopping perspective
A tuba mouthpiece in Yamaha's Standard line, sized like a Bach 25 but with a narrower rim. Suited to students and doublers wanting a smaller feel.

Strong match
Consider the trade-offs
What matters in use
Catalog numbers tell only part of the story. These are the details most likely to change how this product feels, sounds, or fits into a setup.
Detail 01
Bach 25 dimensions with a smaller rim diameter, so the lip contact patch is narrower.
Detail 02
Easier to control in the upper register, less lip freedom for a broad low end.
Detail 03
Yamaha's baseline mouthpiece series, priced for students rather than custom-shop players.
Detail 04
If you know the Bach 25, you know roughly what this feels like before you try it.
Detail 05
One piece only, no pouch, cap, or comparison set of other sizes in the range.
Final check
Product questions
Straight answers to the questions shoppers most often ask about this product.
The 65 matches Bach 25 dimensions. The 64 is the same idea with a smaller rim diameter, so it feels tighter on the lips.
It fits instruments taking a standard tuba shank. Check what your sousaphone receiver accepts before ordering.
It is a standard-line piece rather than a professional model. It is a sensible replacement or spare, not a large upgrade.
The 67B4 in this line follows a Miraphone C3 with a shallower cup, which is described for F tubas. The 64 is not.
Reference
The complete catalog record, organized around the decisions musicians make when comparing gear.