Bob Reeves 40/C/69 vs Conn Imp. Precision 4
The Conn Imp. Precision 4 has a wider cup diameter, the Bob Reeves 40/C/69 features a deeper cup.
Cup Diameter
The Conn Imp. Precision 4 has a cup diameter of 16.41 mm / 0.6461 in compared to 15.88 mm / 0.6252 in on the Bob Reeves 40/C/69 — a difference of 0.53 mm / 0.0209 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
The Bob Reeves 40/C/69 has a deep cup while the Conn Imp. Precision 4 has a medium cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.
Material
The Bob Reeves 40/C/69 is described as unspecified, and the Conn Imp. Precision 4 as Silver-plated brass. 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.