Giardinelli Helleberg vs Schilke 66
The Giardinelli Helleberg has a wider cup diameter, the Giardinelli Helleberg features a deeper cup, the Giardinelli Helleberg has a larger throat opening.
Cup Diameter
The Giardinelli Helleberg has a cup diameter of 33.30 mm / 1.3110 in compared to 31.52 mm / 1.2409 in on the Schilke 66 — a difference of 1.78 mm / 0.0701 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
The Giardinelli Helleberg has a very deep cup while the Schilke 66 has a medium cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.
Throat Diameter
The Giardinelli Helleberg has a wider throat (8.35 mm / 0.3287 in vs 8.33 mm / 0.3280 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.