Bach 1D vs Marcinkiewicz 306
The Marcinkiewicz 306 has a wider cup diameter, the Marcinkiewicz 306 has a larger throat opening.
How deep the cup is, from shallow (brighter, easier high register) to deep (darker, fuller sound).
Mouthpiece A
Bach 1D
• Cornet
Cup depthShallow
vs
Mouthpiece B
Marcinkiewicz 306
• Cornet
Cup depthShallow
Cup Depth
Both mouthpieces share a shallow cup depth, so the sound character from depth alone will be very similar.
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.