Schilke 43A vs Yamaha SL-45C2S
The Yamaha SL-45C2S has a wider cup diameter, the Schilke 43A has a larger throat opening.
The internal diameter of the cup, measured at the widest point inside the rim.
Mouthpiece A
Schilke 43A
• Trombone
Cup diameter23.57 mm / 0.9280 in
Best suited for
High-volume projection — open throat for power
vs
Mouthpiece B
Yamaha SL-45C2S
• Trombone
Cup diameter24.26 mm / 0.9551 in
Best suited for
High-volume projection — open throat for power
Cup Diameter
The Yamaha SL-45C2S has a cup diameter of 24.26 mm / 0.9551 in compared to 23.57 mm / 0.9280 in on the Schilke 43A — a difference of 0.69 mm / 0.0272 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.