Which has a bigger cup — Bach 12E or Kelly BEAST-LS-SS?

The Kelly BEAST-LS-SS has a cup diameter of 28.70 mm / 1.1299 in compared to 24.50 mm / 0.9646 in on the Bach 12E — a difference of 4.20 mm / 0.1654 in. A wider cup generally produces a fuller, darker tone but requires more air support.

How does cup depth compare between Bach 12E and Kelly BEAST-LS-SS?

The Kelly BEAST-LS-SS has a — cup while the Bach 12E has a shallow cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.

Bach 12E vs Kelly BEAST-LS-SS

Name: Kelly BEAST-LS-SS
Brand: Kelly

The Kelly BEAST-LS-SS has a wider cup diameter, the Kelly BEAST-LS-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 12E

• Trombone

Material—

Best suited for

📣High-volume projection — open throat for power

Mouthpiece B

Kelly BEAST-LS-SS

• Trombone

Bass

Material316 Surgical Stainless Steel

Best suited for

🎻Orchestral playing — large cup for full, dark tone

📋Extreme bass trombone; maximum breath support required

Material

The Bach 12E is described as unspecified, and the Kelly BEAST-LS-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 12E details Kelly BEAST-LS-SS details Bach 12E equivalents Kelly BEAST-LS-SS equivalents

Bach 12E vs Kelly BEAST-LS-SS

Material

Playing Characteristics

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