Bach 1¼C vs Yamaha TR-13B4
The Bach 1¼C has a wider cup diameter, the Bach 1¼C features a deeper cup, the Bach 1¼C has a larger throat opening.
The internal diameter of the cup, measured at the widest point inside the rim.
Mouthpiece A
Bach 1¼C
• Trumpet
Cup diameter17.00 mm / 0.6693 in
vs
Mouthpiece B
Yamaha TR-13B4
• Trumpet
Cup diameter16.63 mm / 0.6547 in
Cup Diameter
The Bach 1¼C has a cup diameter of 17.00 mm / 0.6693 in compared to 16.63 mm / 0.6547 in on the Yamaha TR-13B4 — a difference of 0.37 mm / 0.0146 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.