Which has a bigger cup — Conn Imp. Precision 4 or Conn Precision 3?

Both mouthpieces have virtually identical cup diameters at 16.41 mm / 0.6461 in.

How does cup depth compare between Conn Imp. Precision 4 and Conn Precision 3?

Both mouthpieces share a medium cup depth, so the sound character from depth alone will be very similar.

Name: Conn Precision 3
Brand: Conn

Both mouthpieces share similar core dimensions — the differences are in the details.

The width of the rim surface that contacts the lips. Wider rims improve endurance; narrower rims improve flexibility.

Mouthpiece A

Conn Imp. Precision 4

• Cornet

General

Rim width—

Best suited for

🎵All-round versatile — balanced cup for general playing

📋Players with large full lips; most common surviving example

🎶Bright tone; same as Model 3 with wide rim

Mouthpiece B

Conn Precision 3

• Cornet

General

Rim width—

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

Both mouthpieces are categorized as "General" — the physical dimensions above will determine which suits your embouchure and playing style better.