Bach 3C vs GR Technologies 3MS
The GR Technologies 3MS has a wider cup diameter.
The internal diameter of the cup, measured at the widest point inside the rim.
Mouthpiece A
Bach 3C
• Trumpet
Cup diameter16.30 mm / 0.6417 in
Best suited for
All-round versatile — balanced cup for general playing
vs
Mouthpiece B
GR Technologies 3MS
• Trumpet
Cup diameter16.76 mm / 0.6598 in
Cup Diameter
The GR Technologies 3MS has a cup diameter of 16.76 mm / 0.6598 in compared to 16.30 mm / 0.6417 in on the Bach 3C — a difference of 0.46 mm / 0.0181 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.