Yamaha HR-29B vs Yamaha HR-32-GP
The Yamaha HR-32-GP has a wider cup diameter, the Yamaha HR-32-GP features a deeper cup, the Yamaha HR-32-GP has a larger throat opening.
Cup Diameter
The Yamaha HR-32-GP has a cup diameter of 17.48 mm / 0.6882 in compared to 17.07 mm / 0.6720 in on the Yamaha HR-29B — a difference of 0.41 mm / 0.0161 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
The Yamaha HR-32-GP has a medium cup while the Yamaha HR-29B has a shallow cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.
Throat Diameter
The Yamaha HR-32-GP has a wider throat (4.40 mm / 0.1732 in vs 3.90 mm / 0.1535 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.