Which has a bigger cup — Bach 3B or Bach 5B?

The Bach 3B has a cup diameter of 16.30 mm / 0.6417 in compared to 16.25 mm / 0.6398 in on the Bach 5B — a difference of 0.05 mm / 0.0020 in. A wider cup generally produces a fuller, darker tone but requires more air support.

How does cup depth compare between Bach 3B and Bach 5B?

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

Bach 3B vs Bach 5B

Name: Bach 5B
Brand: Bach

The Bach 3B has a wider cup diameter.

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

Surface plating or treatment (e.g. silver plate, gold trim). Affects feel, durability, and appearance.

Mouthpiece A

Bach 3B

• Cornet

Finish—

Mouthpiece B

Bach 5B

• Cornet

Finish—

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.