Bach 12E vs Bob Reeves 11C
The Bob Reeves 11C has a wider cup diameter.
Mouthpiece A
Bach 12E
• Trombone
Cup diameter24.50 mm / 0.9646 in
Cup depthShallow
Rim width—
Throat diameter5.85 mm / 0.2303 in
Backbore—
Finish—
Material—
Best suited for
High-volume projection — open throat for power
vs
Mouthpiece B
Bob Reeves 11C
• Trombone
Cup diameter24.80 mm / 0.9764 in
Cup depthShallow
Rim width—
Throat diameter—
Backbore—
Finish—
Material—
Cup Diameter
The Bob Reeves 11C has a cup diameter of 24.80 mm / 0.9764 in compared to 24.50 mm / 0.9646 in on the Bach 12E — a difference of 0.30 mm / 0.0118 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
Both mouthpieces share a shallow cup depth, so the sound character from depth alone will be very similar.
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.