Marcinkiewicz E14B. Shew #1 vs Yamaha TR-17D4
The Yamaha TR-17D4 has a wider cup diameter, the Yamaha TR-17D4 has a larger throat opening.
Cup Diameter
The Yamaha TR-17D4 has a cup diameter of 17.30 mm / 0.6811 in compared to 16.81 mm / 0.6618 in on the Marcinkiewicz E14B. Shew #1 — a difference of 0.49 mm / 0.0193 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 Yamaha TR-17D4 has a wider throat (3.65 mm / 0.1437 in vs 3.56 mm / 0.1402 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.