Bruno Tilz 211-B 4 vs Kelly MDC
The Bruno Tilz 211-B 4 has a wider cup diameter, the Kelly MDC features a deeper cup, the Kelly MDC has a larger throat opening.
Cup Diameter
The Bruno Tilz 211-B 4 has a cup diameter of 17.50 mm compared to 16.26 mm on the Kelly MDC — a difference of +1.24 mm. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
The Kelly MDC has a — cup while the Bruno Tilz 211-B 4 has a medium cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.
Throat Diameter
The Kelly MDC has a wider throat (4.06 mm vs 4.00 mm). A wider throat allows more air through, increasing volume and projection but reducing resistance.
Material
The Bruno Tilz 211-B 4 is described as unspecified, and the Kelly MDC as Lexan polycarbonate. Material affects mass, warmth, and how quickly the piece responds.
Which is better?
The Bruno Tilz 211-B 4 is designed for catalog playing, while the Kelly MDC targets general use. Your best choice depends on your musical context.