Bach 17D vs Kelly 51D-EU
The Kelly 51D-EU has a wider cup diameter, the Kelly 51D-EU features a deeper cup.
Base metal or construction (e.g. brass, stainless steel, plastic). Influences weight, response, and tone color.
Mouthpiece A
Bach 17D
• Baritone / Euphonium
Material—
Best suited for
High-volume projection — open throat for power
vs
Mouthpiece B
Kelly 51D-EU
• Baritone / Euphonium
ProfessionalMaterialLexan polycarbonate
Best suited for
Orchestral playing — large cup for full, dark tone
Professional euphonium
Material
The Bach 17D is described as unspecified, and the Kelly 51D-EU as Lexan polycarbonate. 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.