GR Technologies 65C** vs Schilke 13A4a
The Schilke 13A4a has a wider cup diameter, the GR Technologies 65C** features a deeper cup.
The internal diameter of the cup, measured at the widest point inside the rim.
Mouthpiece A
GR Technologies 65C**
• Trumpet
Cup diameter16.50 mm / 0.6496 in
vs
Mouthpiece B
Schilke 13A4a
• Trumpet
Cup diameter16.76 mm / 0.6598 in
Cup Diameter
The Schilke 13A4a has a cup diameter of 16.76 mm / 0.6598 in compared to 16.50 mm / 0.6496 in on the GR Technologies 65C** — a difference of 0.26 mm / 0.0102 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.