Bach 8½A vs Conn Connstellation 9BW
The Bach 8½A has a wider cup diameter.
Mouthpiece A
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—
vs
Mouthpiece B
Conn Connstellation 9BW
• Cornet
LeadCup diameter15.88 mm / 0.6252 in
Cup depthVery deep
Rim width—
Throat diameter—
Backbore—
Finish—
MaterialSilver-plated brass
Best suited for
Trumpet players seeking precise matched dimensions
Size 9 (15.88mm); smaller cup; more compact tone; Wide rim; larger rounded inner radius; less bite.
Cup Diameter
The Bach 8½A has a cup diameter of 16.10 mm / 0.6339 in compared to 15.88 mm / 0.6252 in on the Conn Connstellation 9BW — a difference of 0.22 mm / 0.0087 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.
Material
The Bach 8½A is described as unspecified, and the Conn Connstellation 9BW as Silver-plated brass. Material affects mass, warmth, and how quickly the piece responds.
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.