Bruno Tilz 304- T 1 vs Yamaha AH-38D4
The Bruno Tilz 304- T 1 has a wider cup diameter, the Yamaha AH-38D4 has a larger throat opening.
Cup Diameter
The Bruno Tilz 304- T 1 has a cup diameter of 22.00 mm / 0.8661 in compared to 18.90 mm / 0.7441 in on the Yamaha AH-38D4 — a difference of 3.10 mm / 0.1220 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
Both mouthpieces share a deep cup depth, so the sound character from depth alone will be very similar.
Throat Diameter
The Yamaha AH-38D4 has a wider throat (5.25 mm / 0.2067 in vs 4.40 mm / 0.1732 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.