Which has a bigger cup — Bob Reeves 43N/B/X or Kelly 5C?

The Bob Reeves 43N/B/X has a cup diameter of 17.07 mm / 0.6720 in compared to 16.76 mm / 0.6598 in on the Kelly 5C — a difference of 0.31 mm / 0.0122 in. A wider cup generally produces a fuller, darker tone but requires more air support.

How does cup depth compare between Bob Reeves 43N/B/X and Kelly 5C?

Both mouthpieces share a very deep cup depth, so the sound character from depth alone will be very similar.

Bob Reeves 43N/B/X vs Kelly 5C

Name: Kelly 5C
Brand: Kelly

The Bob Reeves 43N/B/X has a wider cup diameter.

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

Bob Reeves 43N/B/X

• Cornet

Material—

Best suited for

🎻Orchestral playing — large cup for full, dark tone

Mouthpiece B

Kelly 5C

• Cornet

General

MaterialLexan polycarbonate

Best suited for

📣High-volume projection — open throat for power

📋Mid-range all-purpose

Material

The Bob Reeves 43N/B/X is described as unspecified, and the Kelly 5C 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.

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Bob Reeves 43N/B/X vs Kelly 5C

Material

Playing Characteristics

What Do These Model Names Mean?

What Changes If You Switch?

Which is better?

Compare Bob Reeves 43N/B/X with others

Compare Kelly 5C with others

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