Bach 11C vs Bach 6½A (small shank)
The Bach 6½A (small shank) has a wider cup diameter, the Bach 6½A (small shank) features a deeper cup.
Mouthpiece A
Bach 11C
• Baritone / Euphonium
Cup diameter24.70 mm
Cup depthShallow
Rim width—
Throat diameter5.85 mm
Backbore—
Finish—
Material—
Best suited for
High-volume projection — open throat for power
vs
Mouthpiece B
Bach 6½A (small shank)
• Baritone / Euphonium
Cup diameter25.40 mm
Cup depthDeep
Rim width—
Throat diameter5.85 mm
Backbore—
Finish—
Material—
Best suited for
Orchestral playing — large cup for full, dark tone
High-volume projection — open throat for power
Cup Diameter
The Bach 6½A (small shank) has a cup diameter of 25.40 mm compared to 24.70 mm on the Bach 11C — a difference of +0.70 mm. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
The Bach 6½A (small shank) has a deep cup while the Bach 11C has a shallow cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.
Throat Diameter
Throat diameters are essentially identical at 5.85 mm, so resistance feel will be comparable.
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.