Curry 132D vs Giardinelli Helleberg
The Curry 132D has a wider cup diameter, the Giardinelli Helleberg has a larger throat opening.
Cup Diameter
The Curry 132D has a cup diameter of 33.53 mm / 1.3200 in compared to 33.30 mm / 1.3110 in on the Giardinelli Helleberg — a difference of 0.23 mm / 0.0090 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
Both mouthpieces share a very deep cup depth, so the sound character from depth alone will be very similar.
Throat Diameter
The Giardinelli Helleberg has a wider throat (8.35 mm / 0.3287 in vs 8.23 mm / 0.3240 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.