Bach 30CB vs Bach 6½AL (large shank)
The Bach 30CB has a wider cup diameter, the Bach 30CB features a deeper cup.
Mouthpiece A
Bach 30CB
• Trombone
Cup diameter30.00 mm / 1.1811 in
Cup depthVery deep
Rim width—
Throat diameter—
Backbore—
Finish—
Material—
Best suited for
Orchestral playing — large cup for full, dark tone
vs
Mouthpiece B
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
Cup Diameter
The Bach 30CB has a cup diameter of 30.00 mm / 1.1811 in compared to 25.40 mm / 1.0000 in on the Bach 6½AL (large shank) — a difference of 4.60 mm / 0.1811 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
The Bach 30CB has a very deep cup while the Bach 6½AL (large shank) has a deep 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.