Which has a bigger cup — Kelly 5G or Yamaha SL-48L-GP?

The Kelly 5G has a cup diameter of 25.40 mm / 1.0000 in compared to 25.25 mm / 0.9941 in on the Yamaha SL-48L-GP — a difference of 0.15 mm / 0.0059 in. A wider cup generally produces a fuller, darker tone but requires more air support.

How does cup depth compare between Kelly 5G and Yamaha SL-48L-GP?

The Kelly 5G has a — cup while the Yamaha SL-48L-GP has a medium cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.

Kelly 5G vs Yamaha SL-48L-GP

Name: Yamaha SL-48L-GP
Brand: Yamaha

The Kelly 5G has a wider cup diameter, the Kelly 5G features a deeper cup.

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 5G

• Trombone

Orchestral

MaterialLexan polycarbonate

Best suited for

🎻Orchestral playing — large cup for full, dark tone

📋Symphonic trombone

Mouthpiece B

Yamaha SL-48L-GP

• Trombone

Material—

Best suited for

📣High-volume projection — open throat for power

Material

The Kelly 5G is described as Lexan polycarbonate, and the Yamaha SL-48L-GP 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.

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Kelly 5G vs Yamaha SL-48L-GP

Material

Playing Characteristics

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