Bruno Tilz 231-T 2 vs Marcinkiewicz ST 3
The Marcinkiewicz ST 3 has a wider cup diameter, the Marcinkiewicz ST 3 has a larger throat opening.
Cup Diameter
The Marcinkiewicz ST 3 has a cup diameter of 32.44 mm / 1.2772 in compared to 32.00 mm / 1.2598 in on the Bruno Tilz 231-T 2 — a difference of 0.44 mm / 0.0173 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
Both mouthpieces share a deep cup depth, so the sound character from depth alone will be very similar.
Throat Diameter
The Marcinkiewicz ST 3 has a wider throat (7.67 mm / 0.3020 in vs 7.20 mm / 0.2835 in). A wider throat allows more air through, increasing volume and projection but reducing resistance.
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.