Kelly 5G-LS vs Yamaha SL-YEO-S

The Yamaha SL-YEO-S has a wider cup diameter, the Kelly 5G-LS features a deeper cup.

Overall Comparison Cup Diameter Cup Depth Rim Width Throat Diameter Backbore Finish Material
The internal diameter of the cup, measured at the widest point inside the rim.
Mouthpiece A
    Kelly 5G-LS
    • Trombone
    Orchestral
    Cup diameter25.40 mm / 1.0000 in
    Best suited for
    🎻Orchestral playing — large cup for full, dark tone
    📋Symphonic trombone / euphonium
    vs
    Mouthpiece B
      Yamaha SL-YEO-S
      • Trombone
      Cup diameter28.72 mm / 1.1307 in
      Best suited for
      🎻Orchestral playing — large cup for full, dark tone
      📣High-volume projection — open throat for power

      Cup Diameter

      The Yamaha SL-YEO-S has a cup diameter of 28.72 mm / 1.1307 in compared to 25.40 mm / 1.0000 in on the Kelly 5G-LS — a difference of 3.32 mm / 0.1307 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.

      Open in interactive tool + Add third mouthpiece Kelly 5G-LS details Yamaha SL-YEO-S details Kelly 5G-LS equivalents Yamaha SL-YEO-S equivalents