Bach 12E vs Schilke 42
The Bach 12E has a wider cup diameter, the Schilke 42 features a deeper cup, the Schilke 42 has a larger throat opening.
The internal diameter of the cup, measured at the widest point inside the rim.
Mouthpiece A
Bach 12E
• Trombone
Cup diameter24.50 mm / 0.9646 in
Best suited for
High-volume projection — open throat for power
vs
Mouthpiece B
Schilke 42
• Trombone
Cup diameter23.22 mm / 0.9142 in
Best suited for
High-volume projection — open throat for power
Cup Diameter
The Bach 12E has a cup diameter of 24.50 mm / 0.9646 in compared to 23.22 mm / 0.9142 in on the Schilke 42 — a difference of 1.28 mm / 0.0504 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.