Bruno Tilz 304- B 1 vs Kelly 51D-EU
The Kelly 51D-EU has a wider cup diameter, the Kelly 51D-EU features a deeper cup.
Cup Diameter
The Kelly 51D-EU has a cup diameter of 25.40 mm compared to 22.00 mm on the Bruno Tilz 304- B 1 — a difference of +3.40 mm. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
The Kelly 51D-EU has a — cup while the Bruno Tilz 304- B 1 has a shallow cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.
Material
The Bruno Tilz 304- B 1 is described as unspecified, and the Kelly 51D-EU as Lexan polycarbonate. Material affects mass, warmth, and how quickly the piece responds.
Which is better?
The Bruno Tilz 304- B 1 is designed for catalog playing, while the Kelly 51D-EU targets professional use. Your best choice depends on your musical context.