Which has a bigger cup — Bach 7C or Bach 9?

The Bach 7C has a cup diameter of 24.75 mm / 0.9744 in compared to 24.72 mm / 0.9732 in on the Bach 9 — a difference of 0.03 mm / 0.0012 in. A wider cup generally produces a fuller, darker tone but requires more air support.

How does cup depth compare between Bach 7C and Bach 9?

The Bach 9 has a deep cup while the Bach 7C has a shallow cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.

Bach 7C vs Bach 9

Name: Bach 9
Brand: Bach

The Bach 7C has a wider cup diameter, the Bach 9 features a deeper cup.

Overall Comparison Cup Diameter Cup Depth Rim Width Throat Diameter Backbore Finish Material

Base metal or construction (e.g. brass, stainless steel, plastic). Influences weight, response, and tone color.

Mouthpiece A

Bach 7C

• Baritone / Euphonium

Material—

Best suited for

📣High-volume projection — open throat for power

Mouthpiece B

Bach 9

• Baritone / Euphonium

Material—

Best suited for

🎻Orchestral playing — large cup for full, dark tone

📣High-volume projection — open throat for power

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.