Bob Reeves 4G vs Bob Reeves 5G

The Bob Reeves 4G has a wider cup diameter, the Bob Reeves 4G features a deeper cup.

Overall Comparison Cup Diameter Cup Depth Rim Width Throat Diameter Backbore Finish Material
Mouthpiece A
    Bob Reeves 4G
    • Trombone
    Cup diameter26.00 mm / 1.0236 in
    Cup depthVery deep
    Rim width
    Throat diameter
    Backbore
    Finish
    Material
    Best suited for
    🎻Orchestral playing — large cup for full, dark tone
    vs
    Mouthpiece B
      Bob Reeves 5G
      • Trombone
      Cup diameter25.55 mm / 1.0059 in
      Cup depthDeep
      Rim width
      Throat diameter
      Backbore
      Finish
      Material
      Best suited for
      🎻Orchestral playing — large cup for full, dark tone

      Cup Diameter

      The Bob Reeves 4G has a cup diameter of 26.00 mm / 1.0236 in compared to 25.55 mm / 1.0059 in on the Bob Reeves 5G — a difference of 0.45 mm / 0.0177 in. A wider cup generally produces a fuller, darker tone but requires more air support.

      Cup Depth

      The Bob Reeves 4G has a very deep cup while the Bob Reeves 5G has a deep cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.

      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 4G details Bob Reeves 5G details Bob Reeves 4G equivalents Bob Reeves 5G equivalents