Bach 30CB vs Bob Reeves CV
The Bach 30CB has a wider cup diameter.
The internal diameter of the cup, measured at the widest point inside the rim.
Mouthpiece A
Bach 30CB
• Trombone
Cup diameter30.00 mm / 1.1811 in
Best suited for
Orchestral playing — large cup for full, dark tone
vs
Mouthpiece B
Bob Reeves CV
• Trombone
Cup diameter29.50 mm / 1.1614 in
Best suited for
Orchestral playing — large cup for full, dark tone
Cup Diameter
The Bach 30CB has a cup diameter of 30.00 mm / 1.1811 in compared to 29.50 mm / 1.1614 in on the Bob Reeves CV — a difference of 0.50 mm / 0.0197 in. A wider cup generally produces a fuller, darker tone but requires more air support.
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.