Bach 4 vs Schilke 57
The Schilke 57 has a wider cup diameter, the Schilke 57 has a larger throat opening.
The internal diameter of the cup, measured at the widest point inside the rim.
Mouthpiece A
Bach 4
• Trombone
Cup diameter26.00 mm / 1.0236 in
Best suited for
High-volume projection — open throat for power
vs
Mouthpiece B
Schilke 57
• Trombone
Cup diameter26.52 mm / 1.0441 in
Best suited for
High-volume projection — open throat for power
Cup Diameter
The Schilke 57 has a cup diameter of 26.52 mm / 1.0441 in compared to 26.00 mm / 1.0236 in on the Bach 4 — a difference of 0.52 mm / 0.0205 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.