Bob Reeves RP4 vs GR Technologies 64Z**
Both mouthpieces share similar core dimensions — the differences are in the details.
The taper behind the throat leading to the shank. Affects projection and tone character.
Mouthpiece A
Bob Reeves RP4
• Trumpet
Backbore—
vs
Mouthpiece B
GR Technologies 64Z**
• Trumpet
Backbore—
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.