GR Technologies 67MX vs Schilke 13A4a
The GR Technologies 67MX has a wider cup diameter, the GR Technologies 67MX features a deeper cup.
The internal diameter of the cup, measured at the widest point inside the rim.
Mouthpiece A
GR Technologies 67MX
• Trumpet
Cup diameter17.00 mm / 0.6693 in
Best suited for
Orchestral playing — large cup for full, dark tone
vs
Mouthpiece B
Schilke 13A4a
• Trumpet
Cup diameter16.76 mm / 0.6598 in
Cup Diameter
The GR Technologies 67MX has a cup diameter of 17.00 mm / 0.6693 in compared to 16.76 mm / 0.6598 in on the Schilke 13A4a — a difference of 0.24 mm / 0.0094 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.