Bach 1¼G vs Yamaha BL-59L-GP
The Bach 1¼G has a wider cup diameter, the Bach 1¼G features a deeper cup, the Yamaha BL-59L-GP has a larger throat opening.
Cup Diameter
The Bach 1¼G has a cup diameter of 27.50 mm / 1.0827 in compared to 27.22 mm / 1.0717 in on the Yamaha BL-59L-GP — a difference of 0.28 mm / 0.0110 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
The Bach 1¼G has a very deep cup while the Yamaha BL-59L-GP has a medium cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.
Throat Diameter
The Yamaha BL-59L-GP has a wider throat (7.25 mm / 0.2854 in vs 7.01 mm / 0.2760 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.