Bach 6½AL (large shank) vs Schilke 53
The Schilke 53 has a wider cup diameter, the Bach 6½AL (large shank) features a deeper cup, the Bach 6½AL (large shank) has a larger throat opening.
The internal diameter of the cup, measured at the widest point inside the rim.
Mouthpiece A
Bach 6½AL (large shank)
• Trombone
Cup diameter25.40 mm / 1.0000 in
Best suited for
Orchestral playing — large cup for full, dark tone
High-volume projection — open throat for power
vs
Mouthpiece B
Schilke 53
• Trombone
Cup diameter26.24 mm / 1.0331 in
Best suited for
High-volume projection — open throat for power
Cup Diameter
The Schilke 53 has a cup diameter of 26.24 mm / 1.0331 in compared to 25.40 mm / 1.0000 in on the Bach 6½AL (large shank) — a difference of 0.84 mm / 0.0331 in. A wider cup generally produces a fuller, darker tone but requires more air support.
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.