Bob Reeves 11C vs Bob Reeves 4G/JF
The Bob Reeves 4G/JF has a wider cup diameter, the Bob Reeves 4G/JF features a deeper cup.
Mouthpiece A
Bob Reeves 11C
• Trombone
Cup diameter24.80 mm / 0.9764 in
Cup depthShallow
Rim width—
Throat diameter—
Backbore—
Finish—
Material—
vs
Mouthpiece B
Bob Reeves 4G/JF
• Trombone
Cup diameter26.00 mm / 1.0236 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/JF has a cup diameter of 26.00 mm / 1.0236 in compared to 24.80 mm / 0.9764 in on the Bob Reeves 11C — a difference of 1.20 mm / 0.0472 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
The Bob Reeves 4G/JF has a deep cup while the Bob Reeves 11C 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.