Bach 6¾C vs Bach 7
The Bach 6¾C has a wider cup diameter, the Bach 7 features a deeper cup.
Mouthpiece A
Bach 6¾C
• Baritone / Euphonium
Cup diameter25.00 mm / 0.9843 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
Bach 7
• Baritone / Euphonium
Cup diameter24.75 mm / 0.9744 in
Cup depthMedium
Rim width—
Throat diameter5.85 mm / 0.2303 in
Backbore—
Finish—
Material—
Best suited for
High-volume projection — open throat for power
Cup Diameter
The Bach 6¾C has a cup diameter of 25.00 mm / 0.9843 in compared to 24.75 mm / 0.9744 in on the Bach 7 — a difference of 0.25 mm / 0.0098 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
The Bach 7 has a medium cup while the Bach 6¾C 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 / 0.2303 in, 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.