Bob Reeves RP4 vs GR Technologies 64Z**

Both mouthpieces share similar core dimensions — the differences are in the details.

Overall Comparison Cup Diameter Cup Depth Rim Width Throat Diameter Backbore Finish Material
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.

      Open in interactive tool + Add third mouthpiece Bob Reeves RP4 details GR Technologies 64Z** details Bob Reeves RP4 equivalents GR Technologies 64Z** equivalents