Bach 6½AL (large shank) vs Bob Reeves 11C
The Bach 6½AL (large shank) has a wider cup diameter, the Bach 6½AL (large shank) features a deeper cup.
Mouthpiece A
Bach 6½AL (large shank)
• Trombone
Cup diameter25.40 mm / 1.0000 in
Cup depthDeep
Rim width—
Throat diameter6.63 mm / 0.2610 in
Backbore—
Finish—
Material—
Best suited for
Orchestral playing — large cup for full, dark tone
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 Bach 6½AL (large shank) has a cup diameter of 25.40 mm / 1.0000 in compared to 24.80 mm / 0.9764 in on the Bob Reeves 11C — a difference of 0.60 mm / 0.0236 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
The Bach 6½AL (large shank) 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.