Bach 5V vs Bach 8½A
The Bach 5V has a wider cup diameter, the Bach 5V has a larger throat opening.
Mouthpiece A
Bach 5V
• Cornet
Cup diameter16.25 mm / 0.6398 in
Cup depthVery deep
Rim width—
Throat diameter4.09 mm / 0.1610 in
Backbore—
Finish—
Material—
Best suited for
High-volume projection — open throat for power
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 5V has a cup diameter of 16.25 mm / 0.6398 in compared to 16.10 mm / 0.6339 in on the Bach 8½A — a difference of 0.15 mm / 0.0059 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
Both mouthpieces share a very deep cup depth, so the sound character from depth alone will be very similar.
Throat Diameter
The Bach 5V has a wider throat (4.09 mm / 0.1610 in vs 3.66 mm / 0.1441 in). A wider throat allows more air through, increasing volume and projection but reducing resistance.
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.