Bach 6½AL (large shank) vs Conn Imp. Precision 4
the Conn Imp. Precision 4 features a deeper cup.
The narrowest point at the bottom of the cup. Affects resistance, volume, and tone color.
Mouthpiece A
Bach 6½AL (large shank)
• Trombone
Throat diameter6.63 mm / 0.2610 in
Best suited for
Orchestral playing — large cup for full, dark tone
High-volume projection — open throat for power
vs
Mouthpiece B
Conn Imp. Precision 4
• Trombone
OrchestralThroat diameter—
Best suited for
Bass trombone / large bore tenor
Full rich deep tone
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.