Conn Precision 4 vs Marcinkiewicz 10
The Marcinkiewicz 10 has a wider cup diameter, the Marcinkiewicz 10 features a deeper cup.
Cup Diameter
The Marcinkiewicz 10 has a cup diameter of 16.84 mm / 0.6630 in compared to 16.41 mm / 0.6461 in on the Conn Precision 4 — a difference of 0.43 mm / 0.0169 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
The Marcinkiewicz 10 has a deep cup while the Conn Precision 4 has a medium cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.
Material
The Conn Precision 4 is described as Silver-plated brass, and the Marcinkiewicz 10 as unspecified. 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.