Kelly MC vs Marcinkiewicz CH 17S
The Marcinkiewicz CH 17S has a wider cup diameter, the Marcinkiewicz CH 17S has a larger throat opening.
Base metal or construction (e.g. brass, stainless steel, plastic). Influences weight, response, and tone color.
Mouthpiece A
Kelly MC
• French Horn
GeneralMaterialLexan polycarbonate
Best suited for
High-volume projection — open throat for power
All-purpose French horn
vs
Mouthpiece B
Marcinkiewicz CH 17S
• French Horn
Material—
Best suited for
Orchestral playing — large cup for full, dark tone
High-volume projection — open throat for power
Material
The Kelly MC is described as Lexan polycarbonate, and the Marcinkiewicz CH 17S as unspecified. Material affects mass, warmth, and how quickly the piece responds.
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.