Which has a bigger cup — Bob Reeves 40/B/X or Kelly 7C?

The Kelly 7C has a cup diameter of 16.51 mm / 0.6500 in compared to 15.88 mm / 0.6252 in on the Bob Reeves 40/B/X — a difference of 0.63 mm / 0.0248 in. A wider cup generally produces a fuller, darker tone but requires more air support.

How does cup depth compare between Bob Reeves 40/B/X and Kelly 7C?

The Bob Reeves 40/B/X has a very deep cup while the Kelly 7C has a medium cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.

Bob Reeves 40/B/X vs Kelly 7C

Name: Kelly 7C
Brand: Kelly

The Kelly 7C has a wider cup diameter, the Bob Reeves 40/B/X 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

Bob Reeves 40/B/X

• Cornet

Material—

Mouthpiece B

Kelly 7C

• Cornet

General

MaterialLexan polycarbonate

Best suited for

🎵All-round versatile — balanced cup for general playing

📋Beginner / intermediate

Material

The Bob Reeves 40/B/X is described as unspecified, and the Kelly 7C 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 Bob Reeves 40/B/X details Kelly 7C details Bob Reeves 40/B/X equivalents Kelly 7C equivalents

Bob Reeves 40/B/X vs Kelly 7C

Material

Playing Characteristics

What Do These Model Names Mean?

What Changes If You Switch?

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