GR Technologies 64.7MS vs Schilke 13A4a
The Schilke 13A4a has a wider cup diameter.
Mouthpiece A
GR Technologies 64.7MS
• Trumpet
Cup diameter16.43 mm / 0.6469 in
Cup depthShallow
Rim width—
Throat diameter—
Backbore—
Finish—
Material—
vs
Mouthpiece B
Schilke 13A4a
• Trumpet
Cup diameter16.76 mm / 0.6598 in
Cup depthShallow
Rim width—
Throat diameter3.66 mm / 0.1441 in
Backbore27
Finish—
Material—
Cup Diameter
The Schilke 13A4a has a cup diameter of 16.76 mm / 0.6598 in compared to 16.43 mm / 0.6469 in on the GR Technologies 64.7MS — 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 shallow 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.