Which has a bigger cup — Bach 8½A or Bach 9D?

The Bach 8½A has a cup diameter of 16.10 mm / 0.6339 in compared to 16.05 mm / 0.6319 in on the Bach 9D — 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 8½A and Bach 9D?

The Bach 8½A has a very deep cup while the Bach 9D has a shallow cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.

Bach 8½A vs Bach 9D

Name: Bach 9D
Brand: Bach

The Bach 8½A has a wider cup diameter, the Bach 8½A features a deeper cup.

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

The narrowest point at the bottom of the cup. Affects resistance, volume, and tone color.

Mouthpiece A

Bach 8½A

• Cornet

Throat diameter3.66 mm / 0.1441 in

Mouthpiece B

Bach 9D

• Cornet

Throat diameter3.66 mm / 0.1441 in

Best suited for

🎺Lead / commercial — shallow cup for brightness and range

Throat Diameter

Throat diameters are essentially identical at 3.66 mm / 0.1441 in, so resistance feel will be comparable.

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.

Open in interactive tool + Add third mouthpiece Bach 8½A details Bach 9D details Bach 8½A equivalents Bach 9D equivalents

Bach 8½A vs Bach 9D

Throat Diameter

Playing Characteristics

What Do These Model Names Mean?

What Changes If You Switch?

Which is better?

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