Kelly MC vs Marcinkiewicz CH R 17S
The Marcinkiewicz CH R 17S has a wider cup diameter, the Marcinkiewicz CH R 17S has a larger throat opening.
The narrowest point at the bottom of the cup. Affects resistance, volume, and tone color.
Mouthpiece A
Kelly MC
• French Horn
GeneralThroat diameter3.80 mm / 0.1496 in
Best suited for
High-volume projection — open throat for power
All-purpose French horn
vs
Mouthpiece B
Marcinkiewicz CH R 17S
• French Horn
Throat diameter4.39 mm / 0.1728 in
Best suited for
Orchestral playing — large cup for full, dark tone
High-volume projection — open throat for power
Throat Diameter
The Marcinkiewicz CH R 17S has a wider throat (4.39 mm / 0.1728 in vs 3.80 mm / 0.1496 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.