Bach 3C vs GR Technologies 64M
The Bach 3C has a wider cup diameter.
Mouthpiece A
Bach 3C
• Trumpet
Cup diameter16.30 mm / 0.6417 in
Cup depthMedium
Rim width—
Throat diameter3.66 mm / 0.1441 in
Backbore—
Finish—
Material—
Best suited for
All-round versatile — balanced cup for general playing
vs
Mouthpiece B
GR Technologies 64M
• Trumpet
Cup diameter16.26 mm / 0.6402 in
Cup depthMedium
Rim width—
Throat diameter—
Backbore—
Finish—
Material—
Best suited for
All-round versatile — balanced cup for general playing
Cup Diameter
The Bach 3C has a cup diameter of 16.30 mm / 0.6417 in compared to 16.26 mm / 0.6402 in on the GR Technologies 64M — a difference of 0.04 mm / 0.0016 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.