Monette Cornet D2.5 S3 vs Yamaha CR-11C4L
The Yamaha CR-11C4L has a wider cup diameter, the Monette Cornet D2.5 S3 has a larger throat opening.
Cup Diameter
The Yamaha CR-11C4L has a cup diameter of 16.46 mm / 0.6480 in compared to 16.40 mm / 0.6457 in on the Monette Cornet D2.5 S3 — a difference of 0.06 mm / 0.0024 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
Both mouthpieces share a medium cup depth, so the sound character from depth alone will be very similar.
Throat Diameter
The Monette Cornet D2.5 S3 has a wider throat (3.66 mm / 0.1441 in vs 3.65 mm / 0.1437 in). A wider throat allows more air through, increasing volume and projection but reducing resistance.
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.