Which has a bigger cup — Kelly 12C or Marcinkiewicz 8H-S?

The Marcinkiewicz 8H-S has a cup diameter of 26.06 mm / 1.0260 in compared to 24.13 mm / 0.9500 in on the Kelly 12C — a difference of 1.93 mm / 0.0760 in. A wider cup generally produces a fuller, darker tone but requires more air support.

How does cup depth compare between Kelly 12C and Marcinkiewicz 8H-S?

Both mouthpieces share a shallow cup depth, so the sound character from depth alone will be very similar.

Kelly 12C vs Marcinkiewicz 8H-S

Name: Marcinkiewicz 8H-S
Brand: Marcinkiewicz

The Marcinkiewicz 8H-S has a wider cup diameter.

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

The taper behind the throat leading to the shank. Affects projection and tone character.

Mouthpiece A

Kelly 12C

• Trombone

Lead

BackboreS

Best suited for

📋Lead trombone; smallest cup

Mouthpiece B

Marcinkiewicz 8H-S

• Trombone

Backbore—

Best suited for

📣High-volume projection — open throat for power

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.