Which has a bigger cup — Bach 5C or GR Technologies G66**?

The GR Technologies G66** has a cup diameter of 16.76 mm / 0.6598 in compared to 16.25 mm / 0.6398 in on the Bach 5C — a difference of 0.51 mm / 0.0201 in. A wider cup generally produces a fuller, darker tone but requires more air support.

How does cup depth compare between Bach 5C and GR Technologies G66**?

Both mouthpieces share a medium cup depth, so the sound character from depth alone will be very similar.

Bach 5C vs GR Technologies G66**

Name: GR Technologies G66**
Brand: GR Technologies

The GR Technologies G66** has a wider cup diameter.

Overall Comparison Cup Diameter Cup Depth Rim Width Throat Diameter Backbore Finish Material

The taper behind the throat leading to the shank. Affects projection and tone character.

Mouthpiece A

Bach 5C

• Trumpet

Backbore—

Best suited for

🎵All-round versatile — balanced cup for general playing

Mouthpiece B

GR Technologies G66**

• Trumpet

Backbore—

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.