Bach 1½G vs Yamaha SL-48S-GP
The Bach 1½G has a wider cup diameter, the Bach 1½G features a deeper cup, the Bach 1½G has a larger throat opening.
Cup Diameter
The Bach 1½G has a cup diameter of 27.00 mm / 1.0630 in compared to 25.25 mm / 0.9941 in on the Yamaha SL-48S-GP — a difference of 1.75 mm / 0.0689 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
The Bach 1½G has a very deep cup while the Yamaha SL-48S-GP has a medium cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.
Throat Diameter
The Bach 1½G has a wider throat (7.01 mm / 0.2760 in vs 6.62 mm / 0.2606 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.