Which has a bigger cup — Kelly 18 or Yamaha BB-BOBO-SOLO-GP?

The Kelly 18 has a cup diameter of 32.77 mm / 1.2902 in compared to 32.20 mm / 1.2677 in on the Yamaha BB-BOBO-SOLO-GP — a difference of 0.57 mm / 0.0224 in. A wider cup generally produces a fuller, darker tone but requires more air support.

How does cup depth compare between Kelly 18 and Yamaha BB-BOBO-SOLO-GP?

The Kelly 18 has a — cup while the Yamaha BB-BOBO-SOLO-GP has a shallow cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.

Kelly 18 vs Yamaha BB-BOBO-SOLO-GP

Name: Yamaha BB-BOBO-SOLO-GP
Brand: Yamaha

The Kelly 18 has a wider cup diameter, the Kelly 18 features a deeper cup.

Overall Comparison Cup Diameter Cup Depth Rim Width Throat Diameter Backbore Finish Material

The narrowest point at the bottom of the cup. Affects resistance, volume, and tone color.

Mouthpiece A

Kelly 18

• Tuba

General

Throat diameter—

Best suited for

🎻Orchestral playing — large cup for full, dark tone

📋Industry-standard tuba

Mouthpiece B

Yamaha BB-BOBO-SOLO-GP

• Tuba

Throat diameter7.50 mm / 0.2953 in

Best suited for

📣High-volume projection — open throat for power

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 18 details Yamaha BB-BOBO-SOLO-GP details Kelly 18 equivalents Yamaha BB-BOBO-SOLO-GP equivalents

Kelly 18 vs Yamaha BB-BOBO-SOLO-GP

Playing Characteristics

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Which is better?

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