Which has a bigger cup — Bach 7A or Bach 9A?

The Bach 7A has a cup diameter of 16.20 mm / 0.6378 in compared to 16.05 mm / 0.6319 in on the Bach 9A — a difference of 0.15 mm / 0.0059 in. A wider cup generally produces a fuller, darker tone but requires more air support.

How does cup depth compare between Bach 7A and Bach 9A?

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

Bach 7A vs Bach 9A

Name: Bach 9A
Brand: Bach

The Bach 7A 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 7A

• Cornet

Finish—

Mouthpiece B

Bach 9A

• 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.