Bach 15 vs Bruno Tilz 304- D 3
The Bach 15 has a wider cup diameter, the Bach 15 features a deeper cup, the Bach 15 has a larger throat opening.
The internal diameter of the cup, measured at the widest point inside the rim.
Mouthpiece A
Bach 15
• Baritone / Euphonium
Cup diameter24.40 mm / 0.9606 in
Best suited for
Orchestral playing — large cup for full, dark tone
High-volume projection — open throat for power
vs
Mouthpiece B
Bruno Tilz 304- D 3
• Baritone / Euphonium
CatalogCup diameter24.00 mm / 0.9449 in
Best suited for
High-volume projection — open throat for power
Cup Diameter
The Bach 15 has a cup diameter of 24.40 mm / 0.9606 in compared to 24.00 mm / 0.9449 in on the Bruno Tilz 304- D 3 — a difference of 0.40 mm / 0.0157 in. A wider cup generally produces a fuller, darker tone but requires more air support.
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.