Bach 18 vs Conn Precision 4
the Conn Precision 4 features a deeper cup.
Mouthpiece A
Bach 18
• Tuba
Cup diameter32.10 mm / 1.2638 in
Cup depthMedium
Rim width—
Throat diameter9.00 mm / 0.3543 in
Backbore—
Finish—
Material—
Best suited for
High-volume projection — open throat for power
vs
Mouthpiece B
Conn Precision 4
• Tuba
GeneralCup diameter—
Cup depthDeep
Rim width—
Throat diameter—
Backbore—
Finish—
MaterialSilver-plated brass
Best suited for
Small Eb bass
Full rich tone
Cup Depth
The Conn Precision 4 has a deep cup while the Bach 18 has a medium cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.
Material
The Bach 18 is described as unspecified, and the Conn Precision 4 as Silver-plated brass. Material affects mass, warmth, and how quickly the piece responds.
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.