GR Technologies 66M vs Schilke 14A4
The Schilke 14A4 has a wider cup diameter.
Mouthpiece A
GR Technologies 66M
• Trumpet
Cup diameter16.76 mm / 0.6598 in
Cup depthMedium
Rim width—
Throat diameter—
Backbore—
Finish—
Material—
vs
Mouthpiece B
Schilke 14A4
• Trumpet
Cup diameter17.09 mm / 0.6728 in
Cup depthMedium
Rim width—
Throat diameter3.66 mm / 0.1441 in
Backbore27
Finish—
Material—
Cup Diameter
The Schilke 14A4 has a cup diameter of 17.09 mm / 0.6728 in compared to 16.76 mm / 0.6598 in on the GR Technologies 66M — a difference of 0.33 mm / 0.0130 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.
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.