Kelly 31 vs Yamaha HR-35C4

The Yamaha HR-35C4 has a wider cup diameter, the Kelly 31 features a deeper cup, the Yamaha HR-35C4 has a larger throat opening.

Overall Comparison Cup Diameter Cup Depth Rim Width Throat Diameter Backbore Finish Material
Base metal or construction (e.g. brass, stainless steel, plastic). Influences weight, response, and tone color.
Mouthpiece A
    Kelly 31
    • French Horn
    General
    MaterialLexan polycarbonate
    Best suited for
    🎻Orchestral playing — large cup for full, dark tone
    📣High-volume projection — open throat for power
    📋French horn deep cup
    vs
    Mouthpiece B
      Yamaha HR-35C4
      • French Horn
      Material
      Best suited for
      📣High-volume projection — open throat for power

      Material

      The Kelly 31 is described as Lexan polycarbonate, and the Yamaha HR-35C4 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.

      Open in interactive tool + Add third mouthpiece Kelly 31 details Yamaha HR-35C4 details Kelly 31 equivalents Yamaha HR-35C4 equivalents