Bach 16 vs Kelly MDC
The Kelly MDC has a wider cup diameter, the Kelly MDC features a deeper cup, the Bach 16 has a larger throat opening.
Cup Diameter
The Kelly MDC has a cup diameter of 16.26 mm / 0.6402 in compared to 16.25 mm / 0.6398 in on the Bach 16 — a difference of 0.01 mm / 0.0004 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
The Kelly MDC has a — cup while the Bach 16 has a very deep cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.
Throat Diameter
The Bach 16 has a wider throat (4.50 mm / 0.1772 in vs 4.06 mm / 0.1598 in). A wider throat allows more air through, increasing volume and projection but reducing resistance.
Material
The Bach 16 is described as unspecified, and the Kelly MDC as Lexan polycarbonate. 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.