Bach 12E vs Bob Reeves CV
The Bob Reeves CV has a wider cup diameter, the Bob Reeves CV features a deeper cup.
The internal diameter of the cup, measured at the widest point inside the rim.
Mouthpiece A
Bach 12E
• Trombone
Cup diameter24.50 mm / 0.9646 in
Best suited for
High-volume projection — open throat for power
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 Bob Reeves CV has a cup diameter of 29.50 mm / 1.1614 in compared to 24.50 mm / 0.9646 in on the Bach 12E — a difference of 5.00 mm / 0.1969 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.