Bach 6½AL (large shank) vs Marcinkiewicz CH 105
The Marcinkiewicz CH 105 has a wider cup diameter, the Marcinkiewicz CH 105 features a deeper cup, the Marcinkiewicz CH 105 has a larger throat opening.
Cup Diameter
The Marcinkiewicz CH 105 has a cup diameter of 29.44 mm / 1.1591 in compared to 25.40 mm / 1.0000 in on the Bach 6½AL (large shank) — a difference of 4.04 mm / 0.1591 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
The Marcinkiewicz CH 105 has a very deep cup while the Bach 6½AL (large shank) has a deep cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.
Throat Diameter
The Marcinkiewicz CH 105 has a wider throat (8.03 mm / 0.3161 in vs 6.63 mm / 0.2610 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.