Bach 1B vs Conn Connstellation 9BN
The Bach 1B has a wider cup diameter, the Conn Connstellation 9BN features a deeper cup.
The internal diameter of the cup, measured at the widest point inside the rim.
Mouthpiece A
Bach 1B
• Cornet
Cup diameter17.00 mm / 0.6693 in
Best suited for
Orchestral playing — large cup for full, dark tone
vs
Mouthpiece B
Conn Connstellation 9BN
• Cornet
LeadCup diameter15.88 mm / 0.6252 in
Best suited for
Trumpet players seeking precise matched dimensions
Size 9 (15.88mm); smaller cup; more compact tone; Narrow rim; smaller inner radius; sharper bite. Fa
Cup Diameter
The Bach 1B has a cup diameter of 17.00 mm / 0.6693 in compared to 15.88 mm / 0.6252 in on the Conn Connstellation 9BN — a difference of 1.12 mm / 0.0441 in. A wider cup generally produces a fuller, darker tone but requires more air support.
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.