Bach 1G vs Yamaha SL-YEO-GP
The Yamaha SL-YEO-GP has a wider cup diameter, the Bach 1G features a deeper cup, the Bach 1G has a larger throat opening.
Cup Diameter
The Yamaha SL-YEO-GP has a cup diameter of 28.72 mm / 1.1307 in compared to 28.00 mm / 1.1024 in on the Bach 1G — a difference of 0.72 mm / 0.0283 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
The Bach 1G has a very deep cup while the Yamaha SL-YEO-GP has a deep cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.
Throat Diameter
The Bach 1G has a wider throat (8.10 mm / 0.3189 in vs 8.00 mm / 0.3150 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.