Bach 1¼GM vs Bach 12E
The Bach 1¼GM has a wider cup diameter, the Bach 1¼GM features a deeper cup, the Bach 1¼GM has a larger throat opening.
Cup Diameter
The Bach 1¼GM has a cup diameter of 27.50 mm / 1.0827 in compared to 24.50 mm / 0.9646 in on the Bach 12E — a difference of 3.00 mm / 0.1181 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
The Bach 1¼GM has a very deep cup while the Bach 12E has a shallow cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.
Throat Diameter
The Bach 1¼GM has a wider throat (8.10 mm / 0.3189 in vs 5.85 mm / 0.2303 in). A wider throat allows more air through, increasing volume and projection but reducing resistance.
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.