Schilke 58 vs Yamaha BL-60L
The Yamaha BL-60L has a wider cup diameter, the Yamaha BL-60L has a larger throat opening.
Cup Diameter
The Yamaha BL-60L has a cup diameter of 28.25 mm / 1.1122 in compared to 27.68 mm / 1.0898 in on the Schilke 58 — a difference of 0.57 mm / 0.0224 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
Both mouthpieces share a medium cup depth, so the sound character from depth alone will be very similar.
Throat Diameter
The Yamaha BL-60L has a wider throat (8.10 mm / 0.3189 in vs 7.54 mm / 0.2969 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.