Bach 12E vs Conn Precision 3A
the Conn Precision 3A features a deeper cup.
The narrowest point at the bottom of the cup. Affects resistance, volume, and tone color.
Mouthpiece A
Bach 12E
• Trombone
Throat diameter5.85 mm / 0.2303 in
Best suited for
High-volume projection — open throat for power
vs
Mouthpiece B
Conn Precision 3A
• Trombone
GeneralThroat diameter—
Best suited for
General trombone use
Good round tone in all registers; all-around
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.