Bach 5C vs GR Technologies 65SZ
The GR Technologies 65SZ has a wider cup diameter, the Bach 5C features a deeper cup.
The internal diameter of the cup, measured at the widest point inside the rim.
Mouthpiece A
Bach 5C
• Trumpet
Cup diameter16.25 mm / 0.6398 in
Best suited for
All-round versatile — balanced cup for general playing
vs
Mouthpiece B
GR Technologies 65SZ
• Trumpet
Cup diameter16.50 mm / 0.6496 in
Cup Diameter
The GR Technologies 65SZ has a cup diameter of 16.50 mm / 0.6496 in compared to 16.25 mm / 0.6398 in on the Bach 5C — a difference of 0.25 mm / 0.0098 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.