Bach 3C vs Bob Reeves RP5
The Bob Reeves RP5 has a wider cup diameter, the Bach 3C features a deeper cup.
Mouthpiece A
Bach 3C
• Trumpet
Cup diameter16.30 mm / 0.6417 in
Cup depthMedium
Rim width—
Throat diameter3.66 mm / 0.1441 in
Backbore—
Finish—
Material—
Best suited for
All-round versatile — balanced cup for general playing
vs
Mouthpiece B
Bob Reeves RP5
• Trumpet
Cup diameter16.47 mm / 0.6484 in
Cup depthShallow
Rim width—
Throat diameter—
Backbore—
Finish—
Material—
Cup Diameter
The Bob Reeves RP5 has a cup diameter of 16.47 mm / 0.6484 in compared to 16.30 mm / 0.6417 in on the Bach 3C — a difference of 0.17 mm / 0.0067 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
The Bach 3C has a medium cup while the Bob Reeves RP5 has a shallow 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.