Detail 01
Size 18
In Bach's tuba numbering, larger numbers mean smaller cups. This sits toward the smaller end of their low brass range.

Independent shopping perspective
Bach size 18 mouthpiece for tuba or sousaphone. For low brass players who want one piece that works across both horns.


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
In Bach's tuba numbering, larger numbers mean smaller cups. This sits toward the smaller end of their low brass range.
Detail 02
Built to seat in both receivers, so one mouthpiece follows you from marching season into concert season.
Detail 03
Less air demanded per note, which helps endurance on long marching sets but gives up some low-register weight.
Detail 04
Mid-range for a low brass mouthpiece. Above stock school pieces, below custom and boutique work.
Final check

Product questions
Straight answers to the questions shoppers most often ask about this product.
Yes, that is what it is built for. Confirm the shank seats properly in each instrument you plan to use it with.
Toward the smaller end of Bach's tuba sizes. Larger Bach numbers indicate smaller cups, which is the opposite of some other makers.
The smaller cup asks for less air per note, which helps on long sets. Many marching players use one piece for both seasons.
A smaller cup tends to make the low register lighter and the upper register easier. Expect an adjustment period either way.
Reference
The complete catalog record, organized around the decisions musicians make when comparing gear.