Bach 1½C vs Conn Precision 1
The Bach 1½C has a wider cup diameter, the Conn Precision 1 features a deeper cup.
The internal diameter of the cup, measured at the widest point inside the rim.
Mouthpiece A
Bach 1½C
• Cornet
Cup diameter17.00 mm / 0.6693 in
vs
Mouthpiece B
Conn Precision 1
• Cornet
GeneralCup diameter16.56 mm / 0.6520 in
Best suited for
All-around players; comfortable wide rim
Full round tone; suited to low notes
Cup Diameter
The Bach 1½C has a cup diameter of 17.00 mm / 0.6693 in compared to 16.56 mm / 0.6520 in on the Conn Precision 1 — a difference of 0.44 mm / 0.0173 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.