Which has a bigger cup — Bach 24W or Kelly X-SMALL?

The Bach 24W has a cup diameter of 31.25 mm / 1.2303 in compared to 30.73 mm / 1.2098 in on the Kelly X-SMALL — a difference of 0.52 mm / 0.0205 in. A wider cup generally produces a fuller, darker tone but requires more air support.

How does cup depth compare between Bach 24W and Kelly X-SMALL?

The Bach 24W has a medium cup while the Kelly X-SMALL has a shallow cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.

Bach 24W vs Kelly X-SMALL

Name: Kelly X-SMALL
Brand: Kelly

The Bach 24W has a wider cup diameter, the Bach 24W 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

Bach 24W

• Tuba

Material—

Best suited for

📣High-volume projection — open throat for power

Mouthpiece B

Kelly X-SMALL

• Tuba

Student

MaterialLexan polycarbonate

Best suited for

📋Student / Eb tuba / euphonium doubler

Material

The Bach 24W is described as unspecified, and the Kelly X-SMALL 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.

Open in interactive tool + Add third mouthpiece Bach 24W details Kelly X-SMALL details Bach 24W equivalents Kelly X-SMALL equivalents

Bach 24W vs Kelly X-SMALL

Material

Playing Characteristics

What Do These Model Names Mean?

What Changes If You Switch?

Which is better?

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