Bach 1½C vs Conn Precision 3
The Bach 1½C has a wider cup diameter.
Mouthpiece A
Bach 1½C
• Cornet
Cup diameter17.00 mm / 0.6693 in
Cup depthMedium
Rim width—
Throat diameter3.66 mm / 0.1441 in
Backbore—
Finish—
Material—
vs
Mouthpiece B
Conn Precision 3
• Cornet
GeneralCup diameter16.41 mm / 0.6461 in
Cup depthMedium
Rim width—
Throat diameter—
Backbore—
Finish—
MaterialSilver-plated brass
Best suited for
All-round versatile — balanced cup for general playing
All-around use; most popular model
Bright quality of tone in all registers; good all-around
Cup Diameter
The Bach 1½C has a cup diameter of 17.00 mm / 0.6693 in compared to 16.41 mm / 0.6461 in on the Conn Precision 3 — a difference of 0.59 mm / 0.0232 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
Both mouthpieces share a medium cup depth, so the sound character from depth alone will be very similar.
Material
The Bach 1½C is described as unspecified, and the Conn Precision 3 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.