Bach 10 vs Marcinkiewicz CH R 15S
The Marcinkiewicz CH R 15S has a wider cup diameter, the Marcinkiewicz CH R 15S has a larger throat opening.
The internal diameter of the cup, measured at the widest point inside the rim.
Mouthpiece A
Bach 10
• French Horn
Cup diameter16.80 mm / 0.6614 in
Best suited for
Orchestral playing — large cup for full, dark tone
High-volume projection — open throat for power
vs
Mouthpiece B
Marcinkiewicz CH R 15S
• French Horn
Cup diameter17.42 mm / 0.6858 in
Best suited for
Orchestral playing — large cup for full, dark tone
High-volume projection — open throat for power
Cup Diameter
The Marcinkiewicz CH R 15S has a cup diameter of 17.42 mm / 0.6858 in compared to 16.80 mm / 0.6614 in on the Bach 10 — a difference of 0.62 mm / 0.0244 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.