Bach 1½C vs Conn Connstellation 7BW
The Bach 1½C has a wider cup diameter, the Conn Connstellation 7BW features a deeper cup.
Cup Diameter
The Bach 1½C has a cup diameter of 17.00 mm / 0.6693 in compared to 16.42 mm / 0.6465 in on the Conn Connstellation 7BW — a difference of 0.58 mm / 0.0228 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
The Conn Connstellation 7BW has a very deep cup while the Bach 1½C has a medium cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.
Material
The Bach 1½C is described as unspecified, and the Conn Connstellation 7BW 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.