Which has a bigger cup — Bach 6 or Kelly 5G-EU-SS?

The Bach 6 has a cup diameter of 25.50 mm / 1.0039 in compared to 25.40 mm / 1.0000 in on the Kelly 5G-EU-SS — a difference of 0.10 mm / 0.0039 in. A wider cup generally produces a fuller, darker tone but requires more air support.

How does cup depth compare between Bach 6 and Kelly 5G-EU-SS?

The Kelly 5G-EU-SS has a — cup while the Bach 6 has a medium cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.

Bach 6 vs Kelly 5G-EU-SS

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

The Bach 6 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

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

Mouthpiece A

Bach 6

• Baritone / Euphonium

Material—

Best suited for

📣High-volume projection — open throat for power

Mouthpiece B

Kelly 5G-EU-SS

• Baritone / Euphonium

General

Material316 Surgical Stainless Steel

Best suited for

🎻Orchestral playing — large cup for full, dark tone

📋Euphonium general use

Material

The Bach 6 is described as unspecified, and the Kelly 5G-EU-SS as 316 Surgical Stainless Steel. 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 6 details Kelly 5G-EU-SS details Bach 6 equivalents Kelly 5G-EU-SS equivalents

Bach 6 vs Kelly 5G-EU-SS

Material

Playing Characteristics

What Do These Model Names Mean?

What Changes If You Switch?

Which is better?

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