Which has a bigger cup — Bach 17C or Kelly 5G-EU-SS?

The Kelly 5G-EU-SS has a cup diameter of 25.40 mm / 1.0000 in compared to 24.20 mm / 0.9528 in on the Bach 17C — a difference of 1.20 mm / 0.0472 in. A wider cup generally produces a fuller, darker tone but requires more air support.

How does cup depth compare between Bach 17C and Kelly 5G-EU-SS?

The Kelly 5G-EU-SS has a — cup while the Bach 17C has a shallow cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.

Bach 17C vs Kelly 5G-EU-SS

Name: Kelly 5G-EU-SS
Brand: Kelly

The Kelly 5G-EU-SS has a wider cup diameter, the Kelly 5G-EU-SS features a deeper cup.

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

Surface plating or treatment (e.g. silver plate, gold trim). Affects feel, durability, and appearance.

Mouthpiece A

Bach 17C

• Baritone / Euphonium

Finish—

Best suited for

📣High-volume projection — open throat for power

Mouthpiece B

Kelly 5G-EU-SS

• Baritone / Euphonium

General

Finish—

Best suited for

🎻Orchestral playing — large cup for full, dark tone

📋Euphonium general use

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 17C details Kelly 5G-EU-SS details Bach 17C equivalents Kelly 5G-EU-SS equivalents

Bach 17C vs Kelly 5G-EU-SS

Playing Characteristics

What Do These Model Names Mean?

What Changes If You Switch?

Which is better?

Compare Bach 17C with others

Compare Kelly 5G-EU-SS with others

Popular Baritone / Euphonium comparisons

Bach vs Kelly

Browse by specification