GR Technologies X66.8 C* vs Yamaha TR-14B4
The GR Technologies X66.8 C* has a wider cup diameter, the GR Technologies X66.8 C* features a deeper cup.
The taper behind the throat leading to the shank. Affects projection and tone character.
Mouthpiece A
GR Technologies X66.8 C*
• Trumpet
Backbore—
Best suited for
Orchestral playing — large cup for full, dark tone
vs
Mouthpiece B
Yamaha TR-14B4
• Trumpet
BackboreSemi-narrow
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.