Bach 6½AL (large shank) vs Conn Precision 2
Both mouthpieces share similar core dimensions — the differences are in the details.
Mouthpiece A
Bach 6½AL (large shank)
• Trombone
Cup diameter25.40 mm / 1.0000 in
Cup depthDeep
Rim width—
Throat diameter6.63 mm / 0.2610 in
Backbore—
Finish—
Material—
Best suited for
Orchestral playing — large cup for full, dark tone
High-volume projection — open throat for power
vs
Mouthpiece B
Conn Precision 2
• Trombone
LeadCup diameter—
Cup depthDeep
Rim width—
Throat diameter—
Backbore—
Finish—
MaterialSilver-plated brass
Best suited for
Solo work; high register; bright
Big bright tone; excellent solo
Cup Depth
Both mouthpieces share a deep cup depth, so the sound character from depth alone will be very similar.
Material
The Bach 6½AL (large shank) is described as unspecified, and the Conn Precision 2 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.