Bach 1 vs Yamaha TR-14B4
The Bach 1 has a wider cup diameter, the Bach 1 features a deeper cup, the Bach 1 has a larger throat opening.
The internal diameter of the cup, measured at the widest point inside the rim.
Mouthpiece A
Bach 1
• Trumpet
Cup diameter17.50 mm / 0.6890 in
Best suited for
Orchestral playing — large cup for full, dark tone
vs
Mouthpiece B
Yamaha TR-14B4
• Trumpet
Cup diameter16.85 mm / 0.6634 in
Cup Diameter
The Bach 1 has a cup diameter of 17.50 mm / 0.6890 in compared to 16.85 mm / 0.6634 in on the Yamaha TR-14B4 — a difference of 0.65 mm / 0.0256 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.