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

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

Mouthpiece A

Bach 12E

• Trombone

Finish—

Best suited for

📣High-volume projection — open throat for power

Mouthpiece B

Kelly BEAST-LS-SS

• Trombone

Bass

Finish—

Best suited for

🎻Orchestral playing — large cup for full, dark tone

📋Extreme bass trombone; maximum breath support required

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

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