Which has a bigger cup — Bach 5B or Bach 8B?

The Bach 5B has a cup diameter of 16.25 mm / 0.6398 in compared to 16.20 mm / 0.6378 in on the Bach 8B — 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 5B and Bach 8B?

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

Bach 5B vs Bach 8B

Name: Bach 8B
Brand: Bach

The Bach 5B 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 5B

• Cornet

Backbore—

Mouthpiece B

Bach 8B

• Cornet

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.