Bach 14½D vs Yamaha EP-51DL
The Yamaha EP-51DL has a wider cup diameter, the Yamaha EP-51DL features a deeper cup, the Yamaha EP-51DL has a larger throat opening.
Cup Diameter
The Yamaha EP-51DL has a cup diameter of 25.24 mm / 0.9937 in compared to 24.50 mm / 0.9646 in on the Bach 14½D — a difference of 0.74 mm / 0.0291 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
The Yamaha EP-51DL has a deep cup while the Bach 14½D has a shallow cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.
Throat Diameter
The Yamaha EP-51DL has a wider throat (7.11 mm / 0.2799 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.