Marcinkiewicz 13 vs Yamaha CR-8D2S
The Yamaha CR-8D2S has a wider cup diameter, the Yamaha CR-8D2S has a larger throat opening.
Cup Diameter
The Yamaha CR-8D2S has a cup diameter of 16.36 mm / 0.6441 in compared to 16.31 mm / 0.6421 in on the Marcinkiewicz 13 — a difference of 0.05 mm / 0.0020 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 CR-8D2S has a wider throat (4.10 mm / 0.1614 in vs 3.73 mm / 0.1469 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.