Kelly 3W-MELLO vs Marcinkiewicz 7FLD
The Kelly 3W-MELLO has a wider cup diameter, the Kelly 3W-MELLO features a deeper cup, the Kelly 3W-MELLO has a larger throat opening.
Cup Diameter
The Kelly 3W-MELLO has a cup diameter of 18.54 mm / 0.7299 in compared to 17.25 mm / 0.6791 in on the Marcinkiewicz 7FLD — a difference of 1.29 mm / 0.0508 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
The Kelly 3W-MELLO has a — cup while the Marcinkiewicz 7FLD has a very deep cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.
Throat Diameter
The Kelly 3W-MELLO has a wider throat (4.37 mm / 0.1720 in vs 4.32 mm / 0.1701 in). A wider throat allows more air through, increasing volume and projection but reducing resistance.
Material
The Kelly 3W-MELLO is described as Lexan polycarbonate, and the Marcinkiewicz 7FLD as unspecified. 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.