Bach 1D vs Marcinkiewicz 306
The Marcinkiewicz 306 has a wider cup diameter, the Marcinkiewicz 306 has a larger throat opening.
The internal diameter of the cup, measured at the widest point inside the rim.
Mouthpiece A
Bach 1D
• Cornet
Cup diameter17.00 mm / 0.6693 in
vs
Mouthpiece B
Marcinkiewicz 306
• Cornet
Cup diameter17.20 mm / 0.6772 in
Cup Diameter
The Marcinkiewicz 306 has a cup diameter of 17.20 mm / 0.6772 in compared to 17.00 mm / 0.6693 in on the Bach 1D — a difference of 0.20 mm / 0.0079 in. A wider cup generally produces a fuller, darker tone but requires more air support.
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.