Kelly 11 vs Yamaha HR-BACON
The Kelly 11 has a wider cup diameter, the Kelly 11 features a deeper cup, the Yamaha HR-BACON has a larger throat opening.
Cup Diameter
The Kelly 11 has a cup diameter of 18.29 mm compared to 17.99 mm on the Yamaha HR-BACON — a difference of +0.30 mm. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
The Kelly 11 has a — cup while the Yamaha HR-BACON 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-BACON has a wider throat (4.50 mm vs 3.66 mm). A wider throat allows more air through, increasing volume and projection but reducing resistance.
Material
The Kelly 11 is described as Lexan polycarbonate, and the Yamaha HR-BACON as unspecified. Material affects mass, warmth, and how quickly the piece responds.
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.