Which has a bigger cup — Bach 1½C or GR Technologies 3M?

The Bach 1½C has a cup diameter of 17.00 mm / 0.6693 in compared to 16.76 mm / 0.6598 in on the GR Technologies 3M — a difference of 0.24 mm / 0.0094 in. A wider cup generally produces a fuller, darker tone but requires more air support.

How does cup depth compare between Bach 1½C and GR Technologies 3M?

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

Bach 1½C vs GR Technologies 3M

Name: GR Technologies 3M
Brand: GR Technologies

The Bach 1½C 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 1½C

• Trumpet

Backbore—

Mouthpiece B

GR Technologies 3M

• 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.