Bach 12E vs Kelly 5G
The Kelly 5G has a wider cup diameter, the Kelly 5G features a deeper cup.
Base metal or construction (e.g. brass, stainless steel, plastic). Influences weight, response, and tone color.
Mouthpiece A
Bach 12E
• Trombone
Material—
Best suited for
High-volume projection — open throat for power
vs
Mouthpiece B
Kelly 5G
• Trombone
OrchestralMaterialLexan polycarbonate
Best suited for
Orchestral playing — large cup for full, dark tone
Symphonic trombone
Material
The Bach 12E is described as unspecified, and the Kelly 5G 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.