Which has a bigger cup — Bruno Tilz 231-C 4 or Kelly 18?

The Bruno Tilz 231-C 4 has a cup diameter of 33.00 mm / 1.2992 in compared to 32.77 mm / 1.2902 in on the Kelly 18 — a difference of 0.23 mm / 0.0091 in. A wider cup generally produces a fuller, darker tone but requires more air support.

How does cup depth compare between Bruno Tilz 231-C 4 and Kelly 18?

The Kelly 18 has a — cup while the Bruno Tilz 231-C 4 has a deep cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.

Bruno Tilz 231-C 4 vs Kelly 18

Name: Kelly 18
Brand: Kelly

The Bruno Tilz 231-C 4 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

Base metal or construction (e.g. brass, stainless steel, plastic). Influences weight, response, and tone color.

Mouthpiece A

Bruno Tilz 231-C 4

• Tuba

Catalog

Material—

Best suited for

🎻Orchestral playing — large cup for full, dark tone

📣High-volume projection — open throat for power

Mouthpiece B

Kelly 18

• Tuba

General

MaterialLexan polycarbonate

Best suited for

🎻Orchestral playing — large cup for full, dark tone

📋Industry-standard tuba

Material

The Bruno Tilz 231-C 4 is described as unspecified, and the Kelly 18 as Lexan polycarbonate. Material affects mass, warmth, and how quickly the piece responds.

Which is better?

The Bruno Tilz 231-C 4 is designed for catalog playing, while the Kelly 18 targets general use. Your best choice depends on your musical context.

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Bruno Tilz 231-C 4 vs Kelly 18

Material

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