Schilke 29 vs Yamaha HR-30B
The Schilke 29 has a wider cup diameter, the Yamaha HR-30B has a larger throat opening.
Cup Diameter
The Schilke 29 has a cup diameter of 17.53 mm / 0.6902 in compared to 17.27 mm / 0.6799 in on the Yamaha HR-30B — a difference of 0.26 mm / 0.0102 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
Both mouthpieces share a shallow cup depth, so the sound character from depth alone will be very similar.
Throat Diameter
The Yamaha HR-30B has a wider throat (3.90 mm / 0.1535 in vs 3.60 mm / 0.1417 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.