Bach 5C vs Marcinkiewicz E9.3R. Braun
The Marcinkiewicz E9.3R. Braun has a wider cup diameter, the Marcinkiewicz E9.3R. Braun features a deeper cup, the Bach 5C has a larger throat opening.
Cup Diameter
The Marcinkiewicz E9.3R. Braun has a cup diameter of 16.38 mm / 0.6449 in compared to 16.25 mm / 0.6398 in on the Bach 5C — a difference of 0.13 mm / 0.0051 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
The Marcinkiewicz E9.3R. Braun has a deep cup while the Bach 5C has a medium cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.
Throat Diameter
The Bach 5C has a wider throat (3.66 mm / 0.1441 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.