Bach 12E vs Conn Imp. Precision 4
the Conn Imp. Precision 4 features a deeper cup.
Mouthpiece A
Bach 12E
• Trombone
Cup diameter24.50 mm / 0.9646 in
Cup depthShallow
Rim width—
Throat diameter5.85 mm / 0.2303 in
Backbore—
Finish—
Material—
Best suited for
High-volume projection — open throat for power
vs
Mouthpiece B
Conn Imp. Precision 4
• Trombone
OrchestralCup diameter—
Cup depth
Rim width—
Throat diameter—
Backbore—
Finish—
MaterialSilver-plated brass
Best suited for
Bass trombone / large bore tenor
Full rich deep tone
Cup Depth
The Conn Imp. Precision 4 has a — cup while the Bach 12E has a shallow cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.
Material
The Bach 12E is described as unspecified, and the Conn Imp. 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.