Bach 7DW vs Bach 8½A
The Bach 7DW has a wider cup diameter, the Bach 8½A features a deeper cup.
Mouthpiece A
Bach 7DW
• Cornet
Cup diameter16.20 mm / 0.6378 in
Cup depthShallow
Rim width—
Throat diameter3.66 mm / 0.1441 in
Backbore—
Finish—
Material—
Best suited for
Lead / commercial — shallow cup for brightness and range
vs
Mouthpiece B
Bach 8½A
• Cornet
Cup diameter16.10 mm / 0.6339 in
Cup depthVery deep
Rim width—
Throat diameter3.66 mm / 0.1441 in
Backbore—
Finish—
Material—
Cup Diameter
The Bach 7DW has a cup diameter of 16.20 mm / 0.6378 in compared to 16.10 mm / 0.6339 in on the Bach 8½A — a difference of 0.10 mm / 0.0039 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
The Bach 8½A has a very deep cup while the Bach 7DW has a shallow cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.
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.